HP FlexFabric 5800, FlexFabric 5820X IP Multicast Configuration Guide

HPE 5820X & 5800 Switch Series

IP Multicast Configuration Guide

Part number: 5998-7383R Software version: Release 1810 Document version: 6W100-20160129

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Contents

Multicast overview ··························································································· 1

Information transmission techniques ·········································································································· 1 Multicast features ······································································································································· 3 Common notations in multicast ·················································································································· 4

Multicast advantages and applications ······································································································ 4 Multicast models ················································································································································ 4 Multicast architecture ········································································································································· 5

Multicast addresses ··································································································································· 5

Multicast protocols ····································································································································· 9 Multicast packet forwarding mechanism ·········································································································· 11 Multicast support for VPNs ······························································································································ 11

Introduction to VPN instances ·················································································································· 11

Multicast application in VPNs ··················································································································· 12

Configuring IGMP snooping ·········································································· 13

IGMP snooping basic concepts ················································································································ 13

How IGMP snooping operates ················································································································· 15

IGMP snooping proxying ·························································································································· 16

Protocols and standards ·························································································································· 18 IGMP snooping configuration task list ·············································································································· 18 Configuring basic IGMP snooping functions ···································································································· 19

Configuration prerequisites ······················································································································ 19

Enabling IGMP snooping ························································································································· 19

Specifying the version of IGMP snooping ································································································ 20

Setting the maximum number of IGMP snooping forwarding entries ······················································· 20

Configuring static multicast MAC address entries ···················································································· 21 Configuring IGMP snooping port functions ······································································································ 21

Configuration prerequisites ······················································································································ 21

Setting aging timers for dynamic ports ····································································································· 22

Configuring static ports ···························································································································· 22

Configuring a port as a simulated member host ······················································································ 23

Enabling IGMP snooping fast-leave processing ······················································································ 24

Disabling a port from becoming a dynamic router port ············································································ 24 Configuring an IGMP snooping querier ············································································································ 25

Configuration prerequisites ······················································································································ 25

Enabling IGMP snooping querier ············································································································· 25

Configuring parameters for IGMP queries and responses ······································································· 26

Configuring the source IP addresses for IGMP queries ··········································································· 27 Configuring IGMP snooping proxying ·············································································································· 27

Configuration prerequisites ······················································································································ 27

Enabling IGMP snooping proxying ··········································································································· 27

Configuring the source IP addresses for the IGMP messages sent by the proxy ···································· 28 Configuring IGMP snooping policies ················································································································ 28

Configuration prerequisites ······················································································································ 28

Configuring a multicast group filter ··········································································································· 28

Configuring multicast source port filtering ································································································ 29

Enabling dropping unknown multicast data ······························································································ 30

Enabling IGMP report suppression ·········································································································· 31

Setting the maximum number of multicast groups that a port can join ···················································· 31

Enabling multicast group replacement ····································································································· 32

Setting the 802.1p precedence for IGMP messages ··············································································· 33

Configuring a multicast user control policy ······························································································· 33

Enabling the IGMP snooping host tracking function ················································································ 34

Setting the DSCP value for IGMP messages ··························································································· 34 Displaying and maintaining IGMP snooping ···································································································· 35 IGMP snooping configuration examples ·········································································································· 35

Group policy and simulated joining configuration example (in a VLAN) ·················································· 36

Static port configuration example (in a VLAN) ························································································· 38

IGMP snooping querier configuration example ························································································ 41

IGMP snooping proxying configuration example ······················································································ 43

Multicast source and user control policy configuration example ······························································ 46 Troubleshooting IGMP snooping ····················································································································· 50

Layer 2 multicast forwarding cannot function ··························································································· 50

Configured multicast group policy fails to take effect ··············································································· 51 Appendix ·························································································································································· 51

Processing of multicast protocol messages ····························································································· 51

Configuring PIM snooping ············································································· 53

Overview ·························································································································································· 53 Configuring PIM snooping ································································································································ 54 Displaying and maintaining PIM snooping ······································································································· 54 PIM snooping configuration example (in a VLAN) ··························································································· 55 Troubleshooting PIM snooping ························································································································ 57

PIM snooping does not work ···················································································································· 57

Some downstream PIM-capable routers cannot receive multicast data ·················································· 58

Configuring multicast VLANs ········································································ 59

Sub-VLAN-based multicast VLAN ············································································································ 59

Port-based multicast VLAN ······················································································································ 60 Multicast VLAN configuration task list ·············································································································· 61 Configuring a sub-VLAN-based multicast VLAN ······························································································ 61

Configuration prerequisites ······················································································································ 61

Configuration guidelines ··························································································································· 61

Configuration procedure ··························································································································· 61 Configuring a port-based multicast VLAN ········································································································ 62

Configuration prerequisites ······················································································································ 62

Configuring user port attributes ················································································································ 62

Configuring multicast VLAN ports ············································································································ 63 Setting the maximum number of forwarding entries for multicast VLANs ························································ 64 Displaying and maintaining a multicast VLAN ································································································· 64 Multicast VLAN configuration examples ·········································································································· 64

Sub-VLAN-based multicast VLAN configuration example ······································································· 64

Port-based multicast VLAN configuration example ·················································································· 68

Configuring multicast routing and forwarding ················································ 72

Hardware compatibility ····································································································································· 72 Overview ·························································································································································· 72

RPF check mechanism ···························································································································· 72

Static multicast routes ······························································································································ 74

Multicast forwarding across unicast subnets ···························································································· 76

Multicast traceroute ·································································································································· 76 Configuration task list ······································································································································· 77 Enabling IP multicast routing ··························································································································· 78 Configuring multicast routing and forwarding ··································································································· 78

Configuration prerequisites ······················································································································ 78

Configuring static multicast routes ··········································································································· 79

Configuring a multicast routing policy ······································································································ 79

Configuring a multicast forwarding range ································································································· 80

Configuring the multicast forwarding table size ························································································ 80

Tracing a multicast path ··························································································································· 81

Enabling multicast optimization ················································································································ 81 Displaying and maintaining multicast routing and forwarding ·········································································· 82 Multicast routing and forwarding configuration examples ················································································ 83

RPF route change configuration example ································································································ 83

RPF route creation configuration example ······························································································· 85

Multicast forwarding over a GRE tunnel ··································································································· 87 Troubleshooting multicast routing and forwarding ··························································································· 91

Static multicast route failure ····················································································································· 91

Multicast data fails to reach receivers ······································································································ 91

Configuring IGMP ························································································· 92

IGMP versions ·········································································································································· 92

IGMPv1 overview ····································································································································· 92

IGMPv2 enhancements ···························································································································· 94

IGMPv3 enhancements ···························································································································· 94

IGMP SSM mapping ································································································································ 96

IGMP proxying ········································································································································· 97

IGMP support for VPNs ···························································································································· 97

Protocols and standards ·························································································································· 98 IGMP configuration task list ····························································································································· 98 Configuring basic IGMP functions ···················································································································· 98

Configuration prerequisites ······················································································································ 99

Enabling IGMP ········································································································································· 99

Specifying IGMP versions ······················································································································ 100

Configuring an interface as a static member interface ··········································································· 100

Configuring a multicast group filter ········································································································· 101

Setting the maximum number of multicast groups that an interface can join ········································· 101 Adjusting IGMP performance ························································································································· 101

Configuration prerequisites ···················································································································· 101

Configuring Router-Alert option handling methods ················································································ 102

Configuring IGMP query and response parameters ··············································································· 103

Enabling IGMP fast-leave processing ···································································································· 105

Enabling the IGMP host tracking function ······························································································ 105

Setting the DSCP value for IGMP messages ························································································· 106 Configuring IGMP SSM mapping ··················································································································· 106

Configuration prerequisites ···················································································································· 106

Enabling SSM mapping ·························································································································· 107

Configuring SSM mappings ··················································································································· 107 Configuring IGMP proxying ···························································································································· 107

Configuration prerequisites ···················································································································· 107

Enabling IGMP proxying ························································································································ 108

Configuring multicast forwarding on a downstream interface ································································ 108 Displaying and maintaining IGMP ·················································································································· 109 IGMP configuration examples ························································································································ 110

Basic IGMP functions configuration example ························································································· 110

SSM mapping configuration example ···································································································· 112

IGMP proxying configuration example ··································································································· 116 Troubleshooting IGMP ··································································································································· 117

No membership information exists on the receiver-side router ······························································ 117

Membership information is inconsistent on the routers on the same subnet ········································· 118

Configuring PIM ·························································································· 119

PIM-DM ·················································································································································· 119

PIM-SM ·················································································································································· 121

BIDIR-PIM ·············································································································································· 127

Administrative scoping ··························································································································· 130

PIM-SSM ················································································································································ 132

Relationship among PIM protocols ········································································································ 133

PIM support for VPNs ···························································································································· 134

Protocols and standards ························································································································ 134 Configuring PIM-DM ······································································································································ 134

PIM-DM configuration task list ··············································································································· 135

Configuration prerequisites ···················································································································· 135

Enabling PIM-DM ··································································································································· 135

Enabling state-refresh capability ············································································································ 136

Configuring state-refresh parameters ···································································································· 136

Configuring PIM-DM graft retry period ··································································································· 137

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Configuring PIM-SM ······································································································································· 137

PIM-SM configuration task list ················································································································ 137

Configuration prerequisites ···················································································································· 138

Enabling PIM-SM ··································································································································· 138

Configuring an RP ·································································································································· 139

Configuring a BSR ································································································································· 141

Configuring administrative scoping ········································································································ 144

Configuring multicast source registration ······························································································· 146

Disabling switchover to SPT ·················································································································· 147 Configuring BIDIR-PIM ·································································································································· 148

BIDIR-PIM configuration task list ··········································································································· 148

Configuration prerequisites ···················································································································· 148

Enabling PIM-SM ··································································································································· 149

Enabling BIDIR-PIM ······························································································································· 149

Configuring an RP ·································································································································· 150

Configuring a BSR ································································································································· 152

Configuring administrative scoping ········································································································ 155 Configuring PIM-SSM ···································································································································· 157

PIM-SSM configuration task list ············································································································· 157

Configuration prerequisites ···················································································································· 157

Enabling PIM-SM ··································································································································· 157

Configuring the SSM group range ·········································································································· 158 Configuring common PIM features ················································································································ 159

Configuration task list ····························································································································· 159

Configuration prerequisites ···················································································································· 159

Configuring a multicast data filter ··········································································································· 160

Configuring a hello message filter ·········································································································· 160

Configuring PIM hello options ················································································································ 161

Configuring the prune delay ··················································································································· 162

Configuring common PIM timers ············································································································ 163

Configuring join/prune message sizes ··································································································· 164

Configuring PIM to work with BFD ········································································································· 164

Setting the DSCP value for PIM messages ··························································································· 165 Displaying and maintaining PIM ····················································································································· 165 PIM configuration examples ··························································································································· 167

PIM-DM configuration example ·············································································································· 167

PIM-SM non-scoped zone configuration example ················································································· 170

PIM-SM admin-scope zone configuration example ················································································ 175

BIDIR-PIM configuration example ·········································································································· 181

PIM-SSM configuration example ············································································································ 186 Troubleshooting PIM ······································································································································ 188

A multicast distribution tree cannot be built correctly ············································································· 188

Multicast data abnormally terminated on an intermediate router ··························································· 189

RPs cannot join SPT in PIM-SM ············································································································ 190

RPT establishment failure or source registration failure in PIM-SM ······················································· 190

Configuring MSDP ······················································································ 192

How MSDP operates ······························································································································ 192

MSDP support for VPNs ························································································································ 197

Protocols and standards ························································································································ 197 MSDP configuration task list ·························································································································· 198 Configuring basic MSDP functions ················································································································ 198

Configuration prerequisites ···················································································································· 198

Enabling MSDP ······································································································································ 198

Creating an MSDP peer connection ······································································································· 199

Configuring a static RPF peer ················································································································ 199 Configuring an MSDP peer connection ·········································································································· 200

Configuration prerequisites ···················································································································· 200

Configuring MSDP peer description ······································································································· 200

Configuring an MSDP mesh group ········································································································ 200

Configuring MSDP peer connection control ··························································································· 201

Configuring SA message related parameters ································································································ 202

Configuration prerequisites ···················································································································· 202

Configuring SA message content ··········································································································· 202

Configuring SA request messages ········································································································· 203

Configuring SA message filtering rules ·································································································· 203

Configuring the SA cache mechanism ··································································································· 204 Displaying and maintaining MSDP ················································································································· 205 MSDP configuration examples ······················································································································· 205

PIM-SM Inter-domain multicast configuration ························································································ 205

Inter-AS multicast configuration by leveraging static RPF peers ··························································· 210

Anycast RP configuration ······················································································································· 214

SA message filtering configuration ········································································································· 218 Troubleshooting MSDP ·································································································································· 222

MSDP peers stay in down state ············································································································· 222

No SA entries exist in the router's SA cache ························································································· 222

Inter-RP communication faults in Anycast RP application ····································································· 222

Configuring MBGP ······················································································ 224

Overview ························································································································································ 224 Protocols and standards ································································································································ 224 MBGP configuration task list ·························································································································· 224 Configuring basic MBGP functions ················································································································ 225

Configuration prerequisites ···················································································································· 225

Configuration procedure ························································································································· 225 Controlling route advertisement and reception ······························································································ 225

Configuration prerequisites ···················································································································· 226

Configuring MBGP route redistribution ·································································································· 226

Configuring default route redistribution into MBGP ················································································ 226

Configuring MBGP route summarization ································································································ 227

Advertising a default route to an IPv4 MBGP peer or peer group ·························································· 227

Configuring outbound MBGP route filtering ··························································································· 228

Configuring inbound MBGP route filtering ······························································································ 229

Configuring MBGP route dampening ····································································································· 230 Configuring MBGP route attributes ················································································································ 230

Configuration prerequisites ···················································································································· 230

Configuring MBGP route preferences ···································································································· 230

Configuring the default local preference ································································································ 231

Configuring the MED attribute ················································································································ 231

Configuring the NEXT_HOP attribute ···································································································· 231

Configuring the AS_PATH attribute ······································································································· 232 Tuning and optimizing MBGP networks ········································································································· 233

Configuration prerequisites ···················································································································· 233

Configuring MBGP soft reset ················································································································· 233

Enabling the MBGP ORF capability ······································································································· 234

Configuring the maximum number of MBGP ECMP routes ··································································· 235 Configuring a large scale MBGP network ······································································································ 235

Configuration prerequisites ···················································································································· 235

Configuring IPv4 MBGP peer groups ····································································································· 235

Configuring MBGP community ··············································································································· 236

Configuring an MBGP route reflector ····································································································· 237 Displaying and maintaining MBGP ················································································································ 237

Displaying MBGP ··································································································································· 237

Resetting MBGP connections ················································································································ 238

Clearing MBGP information ··················································································································· 239 MBGP configuration example ························································································································ 239

Configuring multicast VPN (available only on the HPE 5800) ····················· 243

MD-VPN overview ·································································································································· 245

Multicast across VPNs ··························································································································· 247

M6VPE ··················································································································································· 249

Protocols and standards ························································································································ 250

How MD-VPN works ······································································································································ 250

Share-MDT establishment ····················································································································· 250

Share-MDT-based delivery ···················································································································· 253

MDT switchover ····································································································································· 257

Multi-AS MD VPN ··································································································································· 258 Multicast VPN configuration task list ·············································································································· 260 Configuring MD-VPN ····································································································································· 261

Configuration prerequisites ···················································································································· 261

Enabling IP multicast routing in a VPN instance ···················································································· 261

Configuring a share-group and an MTI binding ······················································································ 261

Configuring MDT switchover parameters ······························································································· 262

Configuring the RPF vector feature ········································································································ 263

Enabling data-group reuse logging ········································································································ 263 Configuring BGP MDT ··································································································································· 264

Configuration prerequisites ···················································································································· 264

Configuring BGP MDT peers or peer groups ························································································· 264

Configuring a BGP MDT route reflector ································································································· 264 Specifying the source IP address for multicast across VPNs ········································································ 265

Configuration prerequisites ···················································································································· 265

Configuration procedure ························································································································· 266 Displaying and maintaining multicast VPN ···································································································· 266 Multicast VPN configuration examples ·········································································································· 267

Single-AS MD VPN configuration ··········································································································· 267

Multi-AS MD VPN configuration ············································································································· 279

Multicast across VPNs configuration example (on the source-side PE) ················································ 292

Multicast across VPNs configuration example (on the receiver-side PE) ·············································· 294

M6VPE configuration example ··············································································································· 295 Troubleshooting MD-VPN configuration ········································································································ 302

A share-MDT cannot be established ······································································································ 302

An MVRF cannot be created ·················································································································· 302

Configuring MLD snooping ········································································· 304

Basic concepts in MLD snooping ··········································································································· 304

How MLD snooping operates ················································································································· 306

MLD snooping proxying ························································································································· 307

Protocols and standards ························································································································ 308 MLD snooping configuration task list ············································································································· 308 Configuring basic MLD snooping functions ···································································································· 309

Configuration prerequisites ···················································································································· 309

Enabling MLD snooping ························································································································· 309

Specifying the version of MLD snooping ································································································ 310

Setting the maximum number of MLD snooping forwarding entries ······················································ 310

Configuring IPv6 static multicast MAC address entries ········································································· 311 Configuring MLD snooping port functions ······································································································ 312

Configuration prerequisites ···················································································································· 312

Configuring aging timers for dynamic ports ···························································································· 312

Configuring static ports ·························································································································· 313

Configuring a port as a simulated member host ···················································································· 313

Enabling MLD snooping fast-leave processing ······················································································ 314

Disabling a port from becoming a dynamic router port ·········································································· 315 Configuring an MLD snooping querier ··········································································································· 315

Configuration prerequisites ···················································································································· 316

Enabling MLD snooping querier ············································································································· 316

Configuring parameters for MLD queries and responses ······································································ 316

Configuring the source IPv6 addresses for MLD queries ······································································· 317 Configuring MLD snooping proxying ·············································································································· 318

Configuration prerequisites ···················································································································· 318

Enabling MLD snooping proxying ·········································································································· 318

Configuring the source IPv6 addresses for the MLD messages sent by the proxy ································ 318 Configuring an MLD snooping policy ············································································································· 319

Configuration prerequisites ···················································································································· 319

Configuring an IPv6 multicast group filter ······························································································ 319

Configuring IPv6 multicast source port filtering ······················································································ 320

Enabling dropping unknown IPv6 multicast data ··················································································· 320

Enabling MLD report suppression ·········································································································· 321

Setting the maximum number of multicast groups that a port can join ·················································· 321

Enabling IPv6 multicast group replacement ··························································································· 322

Setting the 802.1p precedence for MLD messages ··············································································· 323

Configuring an IPv6 multicast user control policy ·················································································· 323

Enabling the MLD snooping host tracking function ················································································ 324

Setting the DSCP value for MLD messages ·························································································· 325 Displaying and maintaining MLD snooping ···································································································· 325 MLD snooping configuration examples ·········································································································· 326

IPv6 group policy and simulated joining configuration example (in a VLAN) ········································· 326

Static port configuration example (in a VLAN) ······················································································· 328

MLD snooping querier configuration example (in a VLAN) ···································································· 331

MLD snooping proxying configuration example (in a VLAN) ·································································· 333

IPv6 multicast source and user control policy configuration example (in a VLAN) ································ 336 Troubleshooting MLD snooping ····················································································································· 341

Layer 2 multicast forwarding cannot function ························································································· 341

Configured IPv6 multicast group policy fails to take effect ····································································· 341 Appendix ························································································································································ 342

Processing of IPv6 multicast protocol messages ··················································································· 342

Configuring IPv6 PIM snooping ·································································· 343

Overview ························································································································································ 343 Configuring IPv6 PIM snooping ····················································································································· 344 Displaying and maintaining IPv6 PIM snooping ····························································································· 344 IPv6 PIM snooping configuration example (in a VLAN) ················································································· 345 Troubleshooting IPv6 PIM snooping ·············································································································· 347

IPv6 PIM snooping does not work ·········································································································· 347

Some downstream IPv6 PIM-capable routers cannot receive multicast data ········································ 348

Configuring IPv6 multicast VLANs ······························································ 349

Configuration prerequisites ···················································································································· 351

Configuration guidelines ························································································································· 351

Configuration procedure ························································································································· 351 Configuring a port-based IPv6 multicast VLAN ······························································································ 352

Configuration prerequisites ···················································································································· 352

Configuring user port attributes ·············································································································· 352

Configuring IPv6 multicast VLAN ports ·································································································· 353 Setting the maximum number of forwarding entries for IPv6 multicast VLANs ·············································· 354 Displaying and maintaining an IPv6 multicast VLAN ····················································································· 354 IPv6 multicast VLAN configuration examples ································································································ 354

Sub-VLAN-based multicast VLAN configuration example ····································································· 354

Port-based multicast VLAN configuration example ················································································ 358

Configuring IPv6 multicast routing and forwarding ······································ 362

RPF check mechanism ·························································································································· 362

IPv6 multicast forwarding across IPv6 unicast subnets ········································································· 364 Configuration task list ····································································································································· 365 Enabling IPv6 multicast routing ······················································································································ 365 Configuring IPv6 multicast routing and forwarding ························································································ 366

Configuration prerequisites ···················································································································· 366

Configuring an IPv6 multicast routing policy ·························································································· 366

Configuring an IPv6 multicast forwarding range ···················································································· 367

Configuring the IPv6 multicast forwarding table size ············································································· 367 Displaying and maintaining IPv6 multicast routing and forwarding ································································ 368 IPv6 multicast routing and forwarding configuration example ········································································ 369

vii

Troubleshooting IPv6 multicast policy configuration ······················································································ 373

Abnormal termination of IPv6 multicast data ·························································································· 373

Configuring MLD ························································································· 374

MLD versions ········································································································································· 374

How MLDv1 operates ····························································································································· 374

How MLDv2 operates ····························································································································· 376

MLD message types ······························································································································ 377

MLD SSM mapping ································································································································ 379

MLD proxying ········································································································································· 380

MLD support for VPNs ··························································································································· 381

Protocols and standards ························································································································ 381 MLD configuration task list ····························································································································· 381 Configuring basic MLD functions ··················································································································· 382

Configuration prerequisites ···················································································································· 382

Enabling MLD ········································································································································· 382

Configuring the MLD version ·················································································································· 383

Configuring an interface as a static member interface ··········································································· 383

Configuring an IPv6 multicast group filter ······························································································ 384

Setting the maximum number of IPv6 multicast groups that an interface can join ································· 384 Adjusting MLD performance ·························································································································· 385

Configuration prerequisites ···················································································································· 385

Configuring Router-Alert option handling methods ················································································ 385

Configuring MLD query and response parameters ················································································ 386

Enabling MLD fast-leave processing ······································································································ 388

Enabling the MLD host tracking function ································································································ 389

Setting the DSCP value for MLD messages ·························································································· 389 Configuring MLD SSM mapping ···················································································································· 389

Configuration prerequisites ···················································································································· 390

Enabling MLD SSM mapping ················································································································· 390

Configuring MLD SSM mappings ··········································································································· 390 Configuring MLD proxying ····························································································································· 390

Enabling MLD proxying ·························································································································· 391

Configuring IPv6 multicast forwarding on a downstream interface ························································ 391 Displaying and maintaining MLD ··················································································································· 392 MLD configuration examples ························································································································· 393

Basic MLD functions configuration example ·························································································· 393

MLD SSM mapping configuration example ···························································································· 395

MLD proxying configuration example ····································································································· 398 Troubleshooting MLD ····································································································································· 400

No member information exists on the receiver-side router ···································································· 400

Membership information is inconsistent on the routers on the same subnet ········································· 401

Configuring IPv6 PIM ·················································································· 402

IPv6 PIM-DM ·········································································································································· 402

IPv6 PIM-SM ·········································································································································· 405

IPv6 BIDIR-PIM ······································································································································ 410

IPv6 administrative scoping ··················································································································· 413

IPv6 PIM-SSM ········································································································································ 415

Relationship among IPv6 PIM protocols ································································································ 416

IPv6 PIM support for VPNs ···················································································································· 417

Protocols and standards ························································································································ 417 Configuring IPv6 PIM-DM ······························································································································ 417

IPv6 PIM-DM configuration task list ······································································································· 418

Configuration prerequisites ···················································································································· 418

Enabling IPv6 PIM-DM ··························································································································· 418

Enabling state-refresh capability ············································································································ 418

Configuring state refresh parameters ····································································································· 419

Configuring IPv6 PIM-DM graft retry period ··························································································· 419

viii

Configuring IPv6 PIM-SM ······························································································································ 420

IPv6 PIM-SM configuration task list ······································································································· 420

Configuration prerequisites ···················································································································· 421

Enabling IPv6 PIM-SM ··························································································································· 421

Configuring an RP ·································································································································· 422

Configuring a BSR ································································································································· 424

Configuring IPv6 administrative scoping ································································································ 427

Configuring IPv6 multicast source registration ······················································································· 428

Disabling switchover to SPT ·················································································································· 429 Configuring IPv6 BIDIR-PIM ·························································································································· 430

IPv6 BIDIR-PIM configuration task list ··································································································· 430

Configuration prerequisites ···················································································································· 430

Enabling IPv6 PIM-SM ··························································································································· 431

Enabling IPv6 BIDIR-PIM ······················································································································· 431

Configuring an RP ·································································································································· 431

Configuring a BSR ································································································································· 433

Configuring IPv6 administrative scoping ································································································ 436 Configuring IPv6 PIM-SSM ···························································································································· 438

IPv6 PIM-SSM configuration task list ····································································································· 438

Configuration prerequisites ···················································································································· 438

Enabling IPv6 PIM-SM ··························································································································· 438

Configuring the IPv6 SSM group range ································································································· 439 Configuring common IPv6 PIM features ········································································································ 440

Configuration task list ····························································································································· 440

Configuration prerequisites ···················································································································· 440

Configuring an IPv6 multicast data filter ································································································· 441

Configuring a hello message filter ·········································································································· 441

Configuring IPv6 PIM hello options ········································································································ 442

Configuring the prune delay timer ·········································································································· 443

Configuring common IPv6 PIM timers ···································································································· 443

Configuring join/prune message sizes ··································································································· 445

Configuring IPv6 PIM to work with BFD ································································································· 445

Setting the DSCP value for IPv6 PIM messages ··················································································· 446 Displaying and maintaining IPv6 PIM ············································································································ 446 IPv6 PIM configuration examples ·················································································································· 447

IPv6 PIM-DM configuration example ······································································································ 447

IPv6 PIM-SM non-scoped zone configuration example ········································································· 450

IPv6 PIM-SM admin-scope zone configuration example ······································································· 455

IPv6 BIDIR-PIM configuration example ·································································································· 468

IPv6 PIM-SSM configuration example ··································································································· 472 Troubleshooting IPv6 PIM ······························································································································ 475

A multicast distribution tree cannot be built correctly ············································································· 475

IPv6 multicast data is abnormally terminated on an intermediate router ··············································· 476

RPs cannot join the SPT in IPv6 PIM-SM ······························································································ 476

RPT cannot be established or a source cannot register in IPv6 PIM-SM ·············································· 477

Configuring IPv6 MBGP ·············································································· 478

Configuration prerequisites ···················································································································· 479

Configuring an IPv6 MBGP peer ············································································································ 479

Configuring a preferred value for routes from a peer or a peer group ··················································· 479 Controlling route distribution and reception ··································································································· 480

Configuration prerequisites ···················································································································· 480

Injecting a local IPv6 MBGP route ········································································································· 480

Configuring IPv6 MBGP route redistribution ·························································································· 480

Configuring IPv6 MBGP route summarization ······················································································· 481

Advertising a default route to a peer or peer group ················································································ 481

Configuring outbound IPv6 MBGP route filtering ··················································································· 481

Configuring inbound IPv6 MBGP route filtering ····················································································· 482

Configuring IPv6 MBGP route dampening ····························································································· 483

Configuring IPv6 MBGP route attributes ········································································································ 483

Configuration prerequisites ···················································································································· 484

Configuring IPv6 MBGP route preferences ···························································································· 484

Configuring the default local preference ································································································ 484

Configuring the MED attribute ················································································································ 484

Configuring the NEXT_HOP attribute ···································································································· 485

Configuring the AS_PATH attribute ······································································································· 485 Tuning and optimizing IPv6 MBGP networks ································································································· 486

Configuration prerequisites ···················································································································· 486

Configuring IPv6 MBGP soft reset ········································································································· 486

Enabling the IPv6 MBGP ORF capability ······························································································· 487

Configuring the maximum number of ECMP routes ··············································································· 488 Configuring a large scale IPv6 MBGP network ······························································································ 488

Configuration prerequisites ···················································································································· 488

Configuring an IPv6 MBGP peer group ·································································································· 488

Configuring IPv6 MBGP community ······································································································· 489

Configuring an IPv6 MBGP route reflector ····························································································· 490 Displaying and maintaining IPv6 MBGP ········································································································ 490

Displaying IPv6 MBGP ··························································································································· 490

Resetting IPv6 MBGP connections ········································································································ 491

Clearing IPv6 MBGP information ··········································································································· 492 IPv6 MBGP configuration example ················································································································ 492

Document conventions and icons ······························································· 495

Conventions ··················································································································································· 495 Network topology icons ·································································································································· 496

Support and other resources ······································································ 497

Accessing Hewlett Packard Enterprise Support ···························································································· 497 Accessing updates ········································································································································· 497

Websites ················································································································································ 498

Customer self repair ······························································································································· 498

Remote support ······································································································································ 498

Documentation feedback ······················································································································· 498

Index ··········································································································· 499

Multicast overview

As a technique that coexists with unicast and broadcast, the multicast technique effectively addresses the issue of point-to-multipoint data transmission. By enabling high-efficiency point-to-multipoint data transmission over a network, multicast greatly saves network bandwidth and reduces network load.

Using multicast technology, a network operator can easily provide bandwidth-critical and time-critical information services. These services include live webcasting, Web TV, distance learning, telemedicine, Web radio, and real-time video conferencing.

Unless otherwise stated, the term "multicast" in this document refers to IP multicast.

Information transmission techniques

The information transmission techniques include unicast, broadcast, and multicast.

Unicast

In unicast transmission, the information source must send a separate copy of information to each host that needs the information.

Figure 1 Unicast transmission

Host A

Receiver

Host B

Source

Host C

Receiver

Host D

IP network

Packets for Host B

Packets for Host D

Packets for Host E

Receiver

Host E

In Figure 1, assume that Host B, Host D and Host E need the information. A separate transmission channel must be established from the information source to each of these hosts.

In unicast transmission, the traffic transmitted over the network is proportional to the number of hosts that need the information. If a large number of hosts need the information, the information source must send a separate copy of the same information to each of these hosts. Sending many copies can place a tremendous pressure on the information source and the network bandwidth.

Unicast is not suitable for batch transmission of information.

Broadcast

In broadcast transmission, the information source sends information to all hosts on the subnet, even if some hosts do not need the information.

Figure 2 Broadcast transmission

Multicast

In Figure 2, assume that only Host B, Host D, and Host E need the information. If the information is broadcast to the subnet, Host A and Host C also receive it. In addition to information security issues, broadcasting to hosts that do not need the information also causes traffic flooding on the same subnet.

Broadcast is disadvantageous in transmitting data to specific hosts. Moreover, broadcast transmission is a significant waste of network resources.

Unicast and broadcast techniques cannot provide point-to-multipoint data transmissions with the minimum network consumption.

Multicast transmission can solve this problem. When some hosts on the network need multicast information, the information sender, or multicast source, sends only one copy of the information. Multicast distribution trees are built through multicast routing protocols, and the packets are replicated only on nodes where the trees branch.

Figure 3 Multicast transmission

As shown in Figure 3, the multicast source sends only one copy of the information to a multicast group. Host B, Host D and Host E, which are receivers of the information, must join the multicast group. The routers on the network duplicate and forward the information based on the distribution of the group members. Finally, the information is correctly delivered to Host B, Host D, and Host E.

To summarize, multicast has the following advantages:

• Advantages over unicast—Multicast traffic is replicated and distributed until it flows to the

farthest-possible node from the source. The increase of receiver hosts will not remarkably increase the load of the source or the usage of network resources

• Advantages over broadcast—Multicast data is sent only to the receivers that need it. This

reasonably uses network bandwidth and enhances network security. In addition, multicast data is not confined to the same subnet.

Multicast features

Multicast transmission has the following features:

• A multicast group is a multicast receiver set identified by an IP multicast address. Hosts join a

multicast group to become members of the multicast group before they can receive the multicast data addressed to that multicast group. Typically, a multicast source does not need to join a multicast group.

• An information sender is called a "multicast source." A multicast source can send data to

multiple multicast groups at the same time. Multiple multicast sources can send data to the same multicast group at the same time.

• All hosts that have joined a multicast group become members of the multicast group. The group

memberships are dynamic. Hosts can join or leave multicast groups at any time. Multicast groups are not subject to geographic restrictions.

• Routers or Layer 3 switches that support Layer 3 multicast are called "multicast routers" or

"Layer 3 multicast devices." In addition to providing the multicast routing function, a multicast router can also manage multicast group memberships on stub subnets with attached group members. A multicast router itself can be a multicast group member.

For a better understanding of the multicast concept, you can compare multicast transmission to the transmission of TV programs as shown in Table 1.

Table 1 Comparing TV program transmission and multicast transmission

TV transmission Multicast transmission

A TV station transmits a TV program through a channel.

A user tunes the TV set to the channel. A receiver joins the multicast group.

The user starts to watch the TV program transmitted by the TV station through the channel.

The user turns off the TV set or tunes to another channel.

Common notations in multicast

The following notations are commonly used in multicast transmission:

• (*, G)—Rendezvous point tree (RPT), or a multicast packet that any multicast source sends to

multicast group G. Here, the asterisk represents any multicast source, and "G" represents a specific multicast group.

• (S, G)—Shortest path tree (SPT), or a multicast packet that multicast source S sends to

multicast group G. Here, "S" represents a specific multicast source, and "G" represents a specific multicast group.

For more information about the concepts RPT and SPT, see "Configuring PIM" and "Configuring

IPv6 PIM."

A multicast source sends multicast data to a multicast group.

The receiver starts to receive the multicast data that the source is sending to the multicast group.

The receiver leaves the multicast group or joins another group.

Multicast advantages and applications

Multicast advantages

Advantages of the multicast technique include the following:

• Enhanced efficiency—Reduces the processor load of information source servers and network

devices.

• Optimal performance—Reduces redundant traffic.

• Distributed application—Enables point-to-multipoint applications at the price of minimum

network resources.

Multicast applications

The scenarios in which the multicast technique can be effectively applied are:

• Multimedia and streaming applications, such as Web TV, Web radio, and real-time video/audio

conferencing

• Communication for training and cooperative operations, such as distance learning and

telemedicine

• Data warehouse and financial applications (stock quotes)

• Any other point-to-multipoint application for data distribution

Multicast models

Based on how the receivers treat the multicast sources, the multicast models include any-source multicast (ASM), source-filtered multicast (SFM), and source-specific multicast (SSM).

ASM model

In the ASM model, any sender can send information to a multicast group as a multicast source. Receivers can join a multicast group (identified by a group address) and obtain multicast information addressed to that multicast group. In this model, receivers do not know the positions of the multicast sources in advance. However, they can join or leave the multicast group at any time.

SFM model

The SFM model is derived from the ASM model. To a sender, the two models appear to have the same multicast membership architecture.

The SFM model functionally extends the ASM model. The upper-layer software examines the source address of received multicast packets and permits or denies multicast traffic from specific sources. Therefore, receivers can receive the multicast data from only part of the multicast sources. To a receiver, not all multicast sources are valid because they are filtered.

SSM model

Users might be interested in the multicast data from only certain multicast sources. The SSM model provides a transmission service that enables users to specify the multicast sources that they are interested in at the client side.

In the SSM model, receivers have already determined the locations of the multicast sources. This is the main difference between the SSM model and the ASM model. In addition, a different multicast address range than the ASM/SFM model is used in the SSM model. Dedicated multicast forwarding paths are established between receivers and the specified multicast sources.

Multicast architecture

IP multicast addresses the following issues:

• Where should the multicast source transmit information to? (Multicast addressing.)

• What receivers exist on the network? (Host registration.)

• Where is the multicast source that provides data to the receivers? (Multicast source discovery.)

• How should information be transmitted to the receivers? (Multicast routing.)

IP multicast is an end-to-end service. The multicast architecture involves the following parts:

• Addressing mechanism—A multicast source sends information to a group of receivers

through a multicast address.

• Host registration—Receiver hosts can join and leave multicast groups dynamically. This

mechanism is the basis for management of group memberships.

• Multicast routing—A multicast distribution tree (a forwarding path tree for multicast data on the

network) is constructed for delivering multicast data from a multicast source to receivers.

• Multicast applications—A software system that supports multicast applications, such as video

conferencing, must be installed on multicast sources and receiver hosts. The TCP/IP stack must support reception and transmission of multicast data.

Multicast addresses

Network-layer multicast addresses (multicast IP addresses) enables communication between multicast sources and multicast group members. In addition, a technique must be available to map multicast IP addresses to link-layer multicast MAC addresses.

IP multicast addresses

• IPv4 multicast addresses:

Internet Assigned Numbers Authority (IANA) assigned the Class D address space (224.0.0.0 to

239.255.255.255) for IPv4 multicast.

Table 2 Class D IP address blocks and description

Address block Description

Reserved permanent group addresses. The IP address 224.0.0.0 is reserved. Other IP addresses can be used by routing protocols and for topology searching, protocol maintenance, and so

224.0.0.0 to 224.0.0.255

224.0.1.0 to 238.255.255.255

239.0.0.0 to 239.255.255.255

NOTE:

on. Table 3 lists common permanent group addresses. A packet destined for an address in this block is not forwarded beyond the local subnet regardless of the Time to Live (TTL) value in the IP header.

Globally scoped group addresses. This block includes the following types of designated group addresses:

• 232.0.0.0/8—SSM group addresses.

• 233.0.0.0/8—Glop group addresses.

Administratively scoped multicast addresses. These addresses are considered locally unique rather than globally unique, and can be reused in domains administered by different organizations without causing conflicts. For more information, see RFC 2365.

"Glop" is a mechanism for assigning multicast addresses between different ASs. By filling an AS number into the middle two bytes of 233.0.0.0, you get 255 multicast addresses for that AS. For more information, see RFC 2770.

Table 3 Some reserved multicast addresses

Address Description

224.0.0.1 All systems on this subnet, including hosts and routers.

224.0.0.2 All multicast routers on this subnet.

224.0.0.3 Unassigned.

224.0.0.4 DVMRP routers.

224.0.0.5 OSPF routers.

224.0.0.6 OSPF designated routers and backup designated routers.

224.0.0.7 Shared Tree (ST) routers.

224.0.0.8 ST hosts.

224.0.0.9 RIPv2 routers.

224.0.0.11 Mobile agents.

224.0.0.12 DHCP server/relay agent.

224.0.0.13 All Protocol Independent Multicast (PIM) routers.

224.0.0.14 RSVP encapsulation.

224.0.0.15 CBT routers.

224.0.0.16 Designated SBM.

224.0.0.17 All SBMs.

224.0.0.18 Virtual Router Redundancy Protocol (VRRP).

• IPv6 multicast addresses: Figure 4 IPv6 multicast format

The following describes the fields of an IPv6 multicast address as shown in Figure 4:

{ 0xFF—The most significant eight bits are 11111111, which indicates that this address is an

IPv6 multicast address.

{ Flags—The Flags field contains four bits as shown in Figure 5 and described in Table 4.

Figure 5 Flags field format

Table 4 Flags field description

Bit Description

0 Reserved, set to 0.

• When set to 0, it indicates that this address is an IPv6 multicast address without an embedded RP address.

• When set to 1, it indicates that this address is an IPv6 multicast address with an embedded RP address. (The P and T bits must also be set to 1.)

• When set to 0, it indicates that this address is an IPv6 multicast address not based on a unicast prefix.

• When set to 1, it indicates that this address is an IPv6 multicast address based on a unicast prefix. (The T bit must also be set to 1.)

• When set to 0, it indicates that this address is an IPv6

multicast address permanently-assigned by IANA.

• When set to 1, it indicates that this address is a transient, or dynamically assigned IPv6 multicast address.

{ Scope—The Scope field contains four bits, which indicate the scope of the IPv6

internetwork for which the multicast traffic is intended. Table 5 d

escribes the values of the

Scope field.

Table 5 Values of the Scope field

Value Meaning

0, F Reserved.

1 Interface-local scope.

2 Link-local scope.

3 Subnet-local scope.

4 Admin-local scope.

5 Site-local scope.

Value Meaning

6, 7, 9 through D Unassigned.

8 Organization-local scope.

E Global scope.

{ Group ID—The Group ID field contains 112 bits. It uniquely identifies an IPv6 multicast

group in the scope that the Scope field defines.

Ethernet multicast MAC addresses

A multicast MAC address identifies a group of receivers at the data link layer.

• IPv4 multicast MAC addresses:

As defined by IANA, the most significant 24 bits of an IPv4 multicast MAC address are 0x01005E. Bit 25 is 0, and the other 23 bits are the least significant 23 bits of a multicast IPv4 address.

Figure 6 IPv4-to-MAC address mapping

As shown in Figure 6, the most significant four bits of a multicast IPv4 address are 1110, which indicates that this address is a multicast address. Only 23 bits of the remaining 28 bits are mapped to a MAC address, so five bits of the multicast IPv4 address are lost. As a result, 32 multicast IPv4 addresses map to the same IPv4 multicast MAC address. Therefore, in Layer 2 multicast forwarding, a switch might receive some multicast data destined for other IPv4 multicast groups. The upper layer must filter such redundant data.

• IPv6 multicast MAC addresses:

As shown in Figure 7, the

most significant 16 bits of an IPv6 multicast MAC address are 0x3333.

The least significant 32 bits are the least significant 32 bits of a multicast IPv6 address.

Figure 7 An example of IPv6-to-MAC address mapping

Multicast protocols

Multicast protocols include the following categories:

• Layer 3 and Layer 2 multicast protocols:

{ Layer 3 multicast refers to IP multicast operating at the network layer.

Layer 3 multicast protocols—IGMP, MLD, PIM, IPv6 PIM, MSDP, MBGP, and IPv6

MBGP.

{ Layer 2 multicast refers to IP multicast operating at the data link layer.

Layer 2 multicast protocols—IGMP snooping, MLD snooping, PIM snooping, IPv6 PIM

snooping, multicast VLAN, and IPv6 multicast VLAN.

• IPv4 and IPv6 multicast protocols:

{ For IPv4 networks—IGMP snooping, PIM snooping, multicast VLAN, IGMP, PIM, MSDP,

and MBGP.

{ For IPv6 networks—MLD snooping, IPv6 PIM snooping, IPv6 multicast VLAN, MLD, IPv6

PIM, and IPv6 MBGP.

This section provides only general descriptions about applications and functions of the Layer 2 and Layer 3 multicast protocols in a network. For more information about these protocols, see the related chapters.

Layer 3 multicast protocols

Layer 3 multicast protocols include multicast group management protocols and multicast routing protocols.

Figure 8 Positions of Layer 3 multicast protocols

• Multicast group management protocols:

Typically, the Internet Group Management Protocol (IGMP) or Multicast Listener Discovery (MLD) protocol is used between hosts and Layer 3 multicast devices that directly connect to the hosts. These protocols define the mechanism of establishing and maintaining group memberships between hosts and Layer 3 multicast devices.

• Multicast routing protocols:

A multicast routing protocol runs on Layer 3 multicast devices to establish and maintain multicast routes and forward multicast packets correctly and efficiently. Multicast routes constitute loop-free data transmission paths from a data source to multiple receivers, that is, a multicast distribution tree.

In the ASM model, multicast routes include intra-domain routes and inter-domain routes.

{ An intra-domain multicast routing protocol discovers multicast sources and builds multicast

distribution trees within an AS to deliver multicast data to receivers. Among a variety of mature intra-domain multicast routing protocols, Protocol Independent Multicast (PIM) is most widely used. Based on the forwarding mechanism, PIM has dense mode (often referred to as "PIM-DM") and sparse mode (often referred to as "PIM-SM").

{ An inter-domain multicast routing protocol is used for delivery of multicast information

between two ASs. So far, mature solutions include Multicast Source Discovery Protocol (MSDP) and Multicast Border Gateway Protocol (MBGP). MSDP propagates multicast source information among different ASs. MBGP is an extension of the Multiprotocol Border Gateway Protocol (MP-BGP) for exchanging multicast routing information among different ASs.

For the SSM model, multicast routes are not divided into intra-domain routes and inter-domain routes. Because receivers know the position of the multicast source, channels established through PIM-SM are sufficient for the transport of multicast information.

Layer 2 multicast protocols

Layer 2 multicast protocols include IGMP snooping, MLD snooping, PIM snooping, IPv6 PIM snooping, multicast VLAN, and IPv6 multicast VLAN.

Figure 9 Positions of Layer 2 multicast protocols

• IGMP snooping and MLD snooping:

IGMP snooping and MLD snooping are multicast constraining mechanisms that run on Layer 2 devices. They manage and control multicast groups by monitoring and analyzing IGMP or MLD messages exchanged between the hosts and Layer 3 multicast devices. This effectively controls the flooding of multicast data in a Layer 2 network.

• PIM snooping and IPv6 PIM snooping:

PIM snooping and IPv6 PIM snooping run on Layer 2 devices. They determine which ports are interested in multicast data by analyzing the received IPv6 PIM messages. Then, they add the ports to a multicast forwarding entry. In this way, multicast data can be forwarded to only the ports that are interested in the data.

• Multicast VLAN and IPv6 multicast VLAN:

In the traditional multicast-on-demand mode, when users in different VLANs on a Layer 2 device need multicast information, the upstream Layer 3 device must forward a separate copy of the multicast data to each VLAN of the Layer 2 device. When the multicast VLAN or IPv6 multicast VLAN feature is enabled on the Layer 2 device, the Layer 3 multicast device sends

only one copy of multicast to the multicast VLAN or IPv6 multicast VLAN on the Layer 2 device. This approach avoids wasting network bandwidth and placing an extra burden on the Layer 3 device.

Multicast packet forwarding mechanism

In a multicast model, receiver hosts of a multicast group are usually located at different positions of the network. They are identified by the same multicast group address. To deliver multicast packets to these receivers, a multicast source encapsulates the multicast data in an IP packet with the multicast group address as the destination address. Multicast routers on the forwarding paths usually need to forward multicast packets that an incoming interface receives through multiple outgoing interfaces. Compared with a unicast model, a multicast model is more complex in the following aspects:

• To ensure multicast packet transmission in the network, different routing tables are used to

guide multicast forwarding. These routing tables include unicast routing tables and multicast routing tables (for example, the MBGP routing table) specially provided for multicast.

• To process the same multicast information from different peers received on different interfaces,

the multicast device performs a reverse path forwarding (RPF) check on each multicast packet. The result of the RPF check determines whether the packet is forwarded or discarded. The RPF check mechanism is the basis for most multicast routing protocols to implement multicast forwarding.

For more information about the RPF mechanism, see "Configuring multicast routing and forwarding"

and "Configuring IPv6 multicast routing and forwarding."

Multicast support for VPNs

Multicast support for VPNs refers to multicast applied in virtual private networks (VPNs).

Introduction to VPN instances

VPNs must be isolated from one another and from the public network. As shown in Figure 10, VPN A and VPN B separately access the public network through PE devices.

Figure 10 VPN networking diagram

VPN A

CE a2

CE b3

VPN BVPN B

CE a3

PE 3

VPN A

CE b1

CE a1

VPN A

CE b2

PE 1

PE 2

Public network

• The provider (P) device belongs to the public network. The customer edge (CE) devices belong

to their respective VPNs. Each CE device serves its own VPN and maintains only one set of forwarding mechanisms.

• The provider edge (PE) devices connect to the public network and the VPNs. Each PE device

must strictly distinguish the information for different networks, and maintain a separate forwarding mechanism for each network. On a PE device, a set of software and hardware that serve the same network forms an instance. Multiple instances can exist on the same PE device, and an instance can reside on different PE devices. On a PE device, the instance for the public network is called the public network instance, and those for VPNs are called VPN instances.

Multicast application in VPNs

A PE device that supports multicast for VPNs does the following operations:

• Maintains an independent set of multicast forwarding mechanisms for each VPN, including the

multicast protocols, PIM neighbor information, and multicast routing table. In a VPN, the device forwards multicast data based on the forwarding table or routing table for that VPN.

• Implements the isolation between different VPNs.

• Implements information exchange and data conversion between the public network and VPN

instances.

Multicast VPN implements multicast on MPLS L3VPN networks. As shown in Figure 10, when a multicast source in VPN A sends a multicast stream to a multicast group, only the receivers that belong to both the multicast group and VPN A can receive the multicast stream. The multicast data is multicast both in VPN A and on the public network.

Configuring IGMP snooping

This chapter describes IGMP snooping, how to configure IGMP snooping, configuration examples, troubleshooting methods, and an appendix about processing multicast protocol messages.

Overview

IGMP snooping is a multicast constraining mechanism that runs on Layer 2 devices to manage and control multicast groups.

By analyzing received IGMP messages, an IGMP snooping-enabled Layer 2 device establishes mappings between ports and multicast MAC addresses, and forwards multicast data based on these mappings.

As shown in Figure 11, without IGMP to all devices at Layer 2. With IGMP snooping enabled, the Layer 2 switch forwards multicast packets destined for known multicast groups are multicast to only the receivers that require the multicast data at Layer 2. This feature improves bandwidth efficiency, enhances multicast security, and helps per-host accounting for multicast users.

Figure 11 Before and after IGMP snooping is enabled on the Layer 2 device

snooping enabled, the Layer 2 switch floods multicast packets

IGMP snooping basic concepts

This section describes the basic concepts involved in IGMP snooping.

IGMP snooping related ports

As shown in Figure 12, Router A connects to the multicast source, IGMP snooping runs on Switch A and Switch B, and Host A and Host C are receiver hosts as members of a multicast group.

Figure 12 IGMP snooping related ports

The following describes the ports involved in IGMP snooping:

• Router port—Layer 3 multicast device-side port. Layer 3 multicast devices include designated

routers (DRs) and IGMP queriers. In Figure 12, Gig

abitEthernet 1/0/1 of Switch A and GigabitEthernet 1/0/1 of Switch B are router ports. The switch registers all its router ports in its router port list.

Do not confuse the "router port" in IGMP snooping with the "routed interface" commonly known as the "Layer 3 interface." The router port in IGMP snooping is the Layer 2 interface.

• Member port—Multicast receiver-side port. In Figure 12, GigabitEthern

et 1/0/2 and GigabitEthernet 1/0/3 of Switch A and GigabitEthernet 1/0/2 of Switch B are member ports. The switch registers all its member ports in its IGMP snooping forwarding table.

Unless otherwise specified, router ports and member ports in this document include both static and dynamic router ports and member ports.

NOTE:

An IGMP snooping-enabled switch deems that all its ports that receive IGMP general queries with the source IP address other than 0.0.0.0 or that receive PIM hello messages are dynamic router ports. For more information about PIM hello messages, see "Configuring PIM."

Aging timers for dynamic ports in IGMP snooping and related messages and actions

Timer Description

When a port receives an expected message, the

Dynamic router port aging timer

Dynamic member port aging timer

switch starts an aging timer for the port. When the timer expires, the dynamic router port ages out.

When a port dynamically joins a multicast group, the switch starts an aging timer for the port. When the timer expires, the dynamic member

Expected message before expiration

IGMP general query of which the source address is not 0.0.0.0 or PIM hello.

IGMP membership report.

Action after expiration

The switch removes this port from its router port list.

The switch removes this port from the IGMP snooping forwarding table.

Timer Description

port ages out.

NOTE:

In IGMP snooping, only dynamic ports age out. Static ports never age out.

How IGMP snooping operates

An IGMP snooping-enabled switch performs different actions when it receives different IGMP messages.

In this section, the involved ports are dynamic ports. For information about how to configure and remove static ports, see "Configuring static ports."

When receiving a general query

To check for the existence of multicast group members, the IGMP querier periodically sends IGMP general queries to all hosts and routers on the local subnet. All these hosts and routers are indentified by the multicast address 224.0.0.1.

After receiving an IGMP general query, the switch forwards it to all ports in the VLAN, except the port that received the query. The switch also performs one of the following actions:

• If the receiving port is a dynamic router port in the router port list, restarts the aging timer for the

port.

• If the receiving port is not in the router port list, adds it into the router port list as a dynamic

router port. It also starts an aging timer for the port.

Expected message before expiration

Action after expiration

When receiving a membership report

A host sends an IGMP report to the IGMP querier for the following purposes:

• If the host has been a member of a multicast group, responds to the query with an IGMP report.

• Applies for joining a multicast group.

After receiving an IGMP report, the switch forwards it through all router ports in the VLAN. it also resolves the address of the reported multicast group, and looks up the multicast forwarding table for a matching entry:

• If no match is found, the Layer 2 device creates a forwarding entry for the group with the

receiving port as an outing interface. It also marks the receiving port as a dynamic member port and starts an aging timer for the port.

• If a match is found but the receiving port is not in the forwarding entry, the Layer 2 device adds

the port as an outgoing interface to the entry. It also marks the port as a dynamic member port and starts an aging timer for the port.

• If a match is found and the receiving port is in the forwarding entry, the Layer 2 device restarts

the aging timer for the port.

A switch does not forward an IGMP report through a non-router port because of IGMP report suppression mechanism. Assuming the switch forwards a report message through a member port, all attached member receivers will receive the report and suppress their own reports. This makes the switch unable to know whether the reported multicast group still has active members attached to that port. For more information about the IGMP report suppression mechanism, see "Configuring IGMP."

When receiving a leave message

An IGMPv1 host does not send any leave messages when it leaves a multicast group. Therefore, the Layer 2 device cannot immediately update the status of the port that connects to the receiver host. In this case, when the aging timer for the multicast group on the port expires, the Layer 2 device

removes the port from the associated forwarding entry. For a static member port, this mechanism does not take effect.

When an IGMPv2 or IGMPv3 host leaves a multicast group, the host sends an IGMP leave message to the multicast router.

When the switch receives an IGMP leave message on a dynamic member port, the switch first examines whether a forwarding entry matches the group address in the message:.

• If no match is found. the switch directly discards the IGMP leave message.

• If a match is found but the receiving port is not in the forwarding entry, the switch directly

discards the IGMP leave message.

• If a match is found and the receiving port is in the forwarding entry, the switch forwards the

leave message to all router ports in the VLAN. Without knowing whether any other attached hosts are still listening to that group, the switch does not immediately remove the port from the forwarding entry. Instead, it restarts the aging timer for the port.

After receiving the IGMP leave message, the IGMP querier resolves the multicast group address in the message. Then, it sends an IGMP group-specific query to the multicast group through the port that received the leave message.

After receiving the IGMP group-specific query, the switch forwards the query through all its router ports in the VLAN and all member ports of the multicast group. Then, the switch waits for the responding IGMP reports from the directly connected hosts to check for the existence of members for the multicast group. For the port that receives the leave message (assuming that it is a dynamic member port), the Layer 2 device also performs one of the following actions:

• If the port receives an IGMP report before the aging timer expires, the switch restarts the aging

timer for the port.

• If the port does not receive an IGMP report when the aging timer expires, the switch removes

the port from the forwarding entry for the multicast group.

IGMP snooping proxying

You can configure the IGMP snooping proxying function on an edge device to reduce the number of IGMP reports and leave messages sent to its upstream device. The device configured with IGMP snooping proxying is called an IGMP snooping proxy. It is a host from the perspective of its upstream device.

NOTE:

Even though an IGMP snooping proxy is a host from the perspective of its upstream device, the IGMP membership report suppression mechanism for hosts does not affect it. For more information about the IGMP report suppression mechanism for hosts, see "Configuring IGMP."

Figure 13 Network diagram

IP network

Proxy & Querier

Switch A

Host A

Receiver

Host B

IGMP Querier

Router A

Query from Router A

Report from Switch A

Query from Switch A

Report from Host

Host C

Receiver

As shown in Figure 13, Switch A works as an IGMP snooping proxy. As a host from the perspective of the querier Router A, Switch A represents its attached hosts to send membership reports and leave messages to Router A. Tab le 6 lists th

e IGMP messages and their processing on an IGMP snooping

proxy.

Table 6 IGMP message processing on an IGMP snooping proxy

IGMP message Actions

When receiving an IGMP general query, the proxy forwards it to all ports except the port

General query

that receive the query. In addition, the proxy generates a report according to the group membership that it maintains and sends the report out of all router ports.

Group-specific query

Report

Leave

In response to the IGMP group-specific query for a certain multicast group, the proxy sends the report to the group out of all router ports if the forwarding entry for the group still contains a member port.

After receiving a report for a multicast group, the proxy looks up the multicast forwarding table for a matching forwarding entry.

• If a match is found and the matching entry contains the receiving port as a dynamic member port, the proxy restarts the aging timer for the port.

• If a match is found but the matching entry does not contain the receiving port, the proxy adds the port to the forwarding entry. It also marks the port as a dynamic member port and starts an aging timer for the port.

• If no match is found, the proxy creates a forwarding entry for the multicast group with the receiving port as an outgoing interface. It also marks the port as a dynamic member port and starts an aging timer for the port.

In response to an IGMP leave message for a multicast group, the proxy sends a group-specific query out of the receiving port. After making sure that no member port is contained in the forwarding entry for the multicast group, the proxy sends a leave message to the group out of all router ports.

Protocols and standards

RFC 4541, Considerations for Internet Group Management Protocol (IGMP) and Multicast Listener Discovery (MLD) Snooping Switches

IGMP snooping configuration task list

For the configuration tasks in this section, the following rules apply:

• The configurations made in IGMP-snooping view are effective for all VLANs. The configuration

made in VLAN view are effective for only the current VLAN. For a given VLAN, a configuration made in IGMP-snooping view is effective only if you do not make the same configuration in VLAN view.

• The configurations made in IGMP-snooping view are effective for all ports. The configurations

made in Layer 2 Ethernet interface view or Layer 2 aggregate interface view are effective for only the current port. The configurations made in port group view are effective for all ports in only the current port group. For a given port, a configuration made in IGMP-snooping view is effective only if you do not make the same configuration in Layer 2 Ethernet interface view, Layer 2 aggregate interface view, or port group view.

• The IGMP snooping configurations made on Layer 2 aggregate interfaces do not interfere with

the configurations made on member ports. In addition, the configurations made on Layer 2 aggregate interfaces do not take part in aggregation calculations. The configurations made on a member port of the aggregate group will take effect after the port leaves the aggregate group.

Task Remarks

uired.

Optional.

Configuring basic IGMP snooping functions

Configuring IGMP snooping port functions

Configuring an IGMP snooping querier

Configuring IGMP snooping proxying

Enabling IGMP snooping Req

Specifying the version of IGMP snooping Optional.

Setting the maximum number of IGMP snooping forwarding entries

Configuring static multicast MAC address entries Optional.

Setting aging timers for dynamic ports Optional.

Configuring static ports Optional.

Configuring a port as a simulated member host Optional.

Enabling IGMP snooping fast-leave processing Optional.

Disabling a port from becoming a dynamic router port Optional.

Enabling IGMP snooping querier Optional.

Configuring parameters for IGMP queries and responses

Configuring the source IP addresses for IGMP queries Optional.

Enabling IGMP snooping proxying Optional.

Configuring the source IP addresses for the IGMP messages sent by the proxy

Task Remarks

Configuring a multicast group filter Optional.

Configuring multicast source port filtering Optional.

Enabling dropping unknown multicast data Optional.

Enabling IGMP report suppression Optional.

Configuring IGMP snooping policies

Setting the maximum number of multicast groups that a port can join

Enabling multicast group replacement Optional.

Setting the 802.1p precedence for IGMP messages Optional.

Configuring a multicast user control policy Optional.

Enabling the IGMP snooping host tracking function Optional.

Setting the DSCP value for IGMP messages Optional.

Optional.

Configuring basic IGMP snooping functions

This section describes how to configure basic IGMP snooping functions.

Configuration prerequisites

Before you configure basic IGMP snooping functions, complete the following tasks:

• Configure the corresponding VLANs.

• Determine the version of IGMP snooping.

Enabling IGMP snooping

This section describes how to enable IGMP snooping.

Configuration guidelines

• You must enable IGMP snooping globally before you enable it for a VLAN.

• If you enable IGMP snooping for a VLAN, do not enable IGMP or PIM on the corresponding

VLAN interface. If you enable IGMP or PIM on a VLAN interface, do not enable IGMP snooping for the VLAN.

• IGMP snooping for a VLAN works on only the ports in this VLAN.

Configuration procedure

To enable IGMP snooping:

Step Command Remarks

1. Enter system view.

2. Enable IGMP snooping globally

and enter IGMP-snooping view.

3. Return to system view.

4. Enter VLAN view.

system-view

igmp-snooping

quit

vlan

vlan-id

N/A

Disabled by default.

N/A

Step Command Remarks

5. Enable IGMP snooping in the

VLAN.

igmp-snooping enable

Specifying the version of IGMP snooping

Different versions of IGMP snooping can process different versions of IGMP messages:

• IGMPv2 snooping can process IGMPv1 and IGMPv2 messages, but flood IGMPv3 messages

in the VLAN instead of processing them.

• IGMPv3 snooping can process IGMPv1, IGMPv2 and IGMPv3 messages.

If you change IGMPv3 snooping to IGMPv2 snooping, the system does the following:

• Clears all IGMP snooping forwarding entries that are dynamically added.

• Keeps static IGMPv3 snooping forwarding entries (*, G).

• Clears static IGMPv3 snooping forwarding entries (S, G), which will be restored when IGMP

snooping is switched back to IGMPv3 snooping.

For more information about static joins, see "Configuring static ports."

o specify the version of IGMP snooping:

Disabled by default.

Step Command Remarks

1. Enter system view.

2. Enter VLAN view.

3. Specify the version of IGMP

snooping.

system-view vlan vlan-id

igmp-snooping version

version-number

N/A

IGMPv2 snooping by default.

Setting the maximum number of IGMP snooping forwarding entries

You can modify the maximum number of entries in the IGMP snooping forwarding table. When the number of existing forwarding entries reaches the upper limit, the device does not create new entries until some entries time out or are removed. In this case, Hewlett Packard Enterprise recommends that you manually remove some entries, because the device does not automatically remove any existing entries.

To set the maximum number of IGMP snooping forwarding entries:

Step Command Remarks

1. Enter system view.

2. Enter IGMP-snooping view.

3. Set the maximum number of

IGMP snooping forwarding entries.

system-view igmp-snooping

entry-limit

limit

N/A

By default, the upper limit is 4000 for the HPE 5800 switches, and 2000 for the HPE 5820X switches.

NOTE:

IGMP snooping forwarding entries created for multicast VLAN are not limited by this command. You

can use the multicast-vlan entry-limit to limit the number of entries in the IGMP snooping

forwarding table of a multicast VLAN. For more information, see "Configuring multicast VLANs."

Configuring static multicast MAC address entries

In Layer-2 multicast, a Layer 2 multicast protocol (such as IGMP snooping) can dynamically add multicast MAC address entries. Or, you can manually configure multicast MAC address entries.

Configuration guidelines

• You can configure a static multicast MAC address entry for any legal multicast MAC address. A

multicast MAC address is a MAC address in which the least significant bit of the the most significant octet is 1.

• When you configure a static multicast MAC address entry in system view, the configuration is

effective on the specified interfaces. When you configure a static multicast MAC address entry in interface view or port group view, the configuration is effective only on the current interface or all interfaces in the current port group.

Configuration procedure

To configure a static multicast MAC address entry in system view:

Step Command Remarks

1. Enter system view.

system-view

N/A

2. Configure a static multicast

MAC address entry.

To configure a static multicast MAC address entry in interface view:

mac-address multicast

mac-address interface-list

interface

vlan

vlan-id

No static multicast MAC address entries exist by default.

Step Command Remarks

1. Enter system view.

2. Enter Ethernet

interface/Layer 2 aggregate interface view or port group view.

3. Configure a static multicast

MAC address entry.

system-view

• Enter Ethernet interface/Layer 2 aggregate interface view:

interface interface-type interface-number

• Enter port group view:

port-group manual

port-group-name

mac-address multicast

mac-address

vlan

vlan-id

N/A

In Ethernet interface view or Layer 2 aggregate interface view, the configuration is effective on only the current interface. In port group view, the configuration is effective on all ports in the port group.

No static multicast MAC address entries exist by default.

Configuring IGMP snooping port functions

This section describes how to configure IGMP snooping port functions.

Configuration prerequisites

Before you configure IGMP snooping port functions, complete the following tasks:

• Enable IGMP snooping in the VLAN.

• Configure the corresponding port groups.

• Determine the aging timer for dynamic router ports.

• Determine the aging timer for dynamic member ports.

• Determine the multicast group and multicast source addresses.

Setting aging timers for dynamic ports

If the memberships of multicast groups change frequently, you can set a relatively small value for the aging timer of the dynamic member ports. If the memberships of multicast groups change rarely, you can set a relatively large value.

Setting aging timers for dynamic ports globally

Step Command Remarks

1. Enter system view.

2. Enter IGMP-snooping view.

3. Set the aging timer for the

dynamic router ports.

4. Set the aging timer for the

dynamic member ports.

Setting aging timers for the dynamic ports in a VLAN

system-view igmp-snooping

router-aging-time

host-aging-time

interval 105 seconds by default.

interval 260 seconds by default.

N/A

Step Command Remarks

1. Enter system view.

2. Enter VLAN view

3. Set the aging timer for the

dynamic router ports.

4. Set the aging timer for the

dynamic member ports.

Configuring static ports

You can configure a port as a static port for the following purposes:

• To make all the hosts attached to the port receive multicast data addressed to a multicast group,

configure the port as a static member port for the multicast group.

• To make the Layer 2 device attached to the port forward all received multicast traffic on the port,

configure the port as a static router port.

Configuration guidelines

• A static member port does not respond to queries from the IGMP querier. When you configure a

port as a static member port or cancel this configuration on the port, the port does not unsolicitedly send any IGMP report or an IGMP leave message.

• Static member ports and static router ports never age out. To remove such a port, use the corresponding undo command.

system-view vlan igmp-snooping

router-aging-time igmp-snooping host-aging-time

interval

vlan-id

interval

N/A

105 seconds by default.

260 seconds by default.

Configuration procedure

To configure static ports:

Step Command Remarks

1. Enter system view.

system-view

N/A

Step Command Remarks

• Enter Layer 2 Ethernet interface view or Layer 2

2. Enter Layer 2 Ethernet

interface view or Layer 2 aggregate interface view, or enter port group view.

aggregate interface view:

interface interface-type interface-number

• Enter port group view:

port-group manual

port-group-name

Use either command.

3. Configure the port as a static

member port.

4. Configure the port as a static

router port.

igmp-snooping static-group

group-address [ source-address ]

igmp-snooping static-router-port vlan

source-ip

vlan

vlan-id

No static member ports exist by default.

No static router ports exist by default.

Configuring a port as a simulated member host

Generally, a host that runs IGMP can respond to IGMP queries. If a host fails to respond, the multicast router might deem that no member of this multicast group exists on the subnet, and removes the corresponding forwarding path.

To avoid this situation, you can configure the port as a simulated member host for a multicast group. When the simulated member host receives an IGMP query, it gives a response. Therefore, the switch can continue receiving multicast data.

A simulated host is equivalent to a real, independent host in the following ways:

• When a port is configured as a simulated member host, the switch can send an unsolicited

IGMP report through the port. It can also respond to IGMP general queries with IGMP reports through the port.

• When you disable the simulated joining function on the port, the switch sends an IGMP leave

message through the port.

To configure a port as a simulated member host:

Step Command Remarks

1. Enter system view.

2. Enter Layer 2 Ethernet

interface view or Layer 2 aggregate interface view, or enter port group view.

3. Configure the port as a

simulated member host.

NOTE:

system-view

• Enter Layer 2 Ethernet interface view or Layer 2 aggregate interface view:

interface interface-type interface-number

• Enter port group view:

port-group manual

port-group-name

igmp-snooping host-join

source-ip

[

source-address ]

group-address

vlan

vlan-id

N/A

Use either command.

Not configured by default.

Unlike a static member port, a port that you configure as a simulated member host ages out like a dynamic member port.

Enabling IGMP snooping fast-leave processing

IGMP snooping fast-leave processing feature enables the switch to process IGMP leave messages quickly. With IGMP snooping feature enabled, when the switch receives an IGMP leave message on a port, it immediately removes that port from the forwarding entry for the multicast group specified in the message. Then, when the switch receives IGMP group-specific queries for that multicast group, it does not forward them to that port.

On a port that has only one host attached, you can enable IGMP snooping fast-leave processing to save bandwidth and resources. However, on a port that has multiple hosts attached, do not enable IGMP snooping fast-leave processing if dropping unknown multicast data is enabled. Otherwise, if a host on the port leaves a multicast group, the other hosts attached to the port in the same multicast group cannot receive the multicast data for the group.

Enabling IGMP snooping fast-leave processing globally

Step Command Remarks

1. Enter system view.

system-view

N/A

2. Enter IGMP-snooping view.

3. Enable IGMP snooping

fast-leave processing.

igmp-snooping

fast-leave [ vlan

vlan-list

N/A

]

Disabled by default.

Enabling IGMP snooping fast-leave processing on a port

Step Command Remarks

1. Enter system view.

2. Enter Layer 2 Ethernet

interface view or Layer 2 aggregate interface view, or enter port group view.

3. Enable IGMP snooping

fast-leave processing on the port.

system-view

• Enter Layer 2 Ethernet interface view or Layer 2 aggregate interface view:

interface interface-type interface-number

• Enter port group view:

port-group manual

port-group-name

igmp-snooping fast-leave [ vlan

vlan-list

]

N/A

Use either command.

Disabled by default.

Disabling a port from becoming a dynamic router port

The following problems might exist in a multicast access network:

• After receiving an IGMP general query or a PIM hello message from a connected host, a router

port becomes a dynamic router port. Before its timer expires, this dynamic router port receives all multicast packets within the VLAN where the port belongs, and forwards them to the host, affecting normal multicast reception of the host.

• In addition, the IGMP general query or PIM hello message that the host sends affects the

multicast routing protocol state on Layer 3 devices, such as the IGMP querier or DR election. This might further cause network interruption.

To solve these problems, after the router port receives an IGMP general query or a PIM hello message, disable the port from becoming a dynamic router port. This enhances network security and the control over multicast users.

To disable a port from becoming a dynamic router port:

Step Command Remarks

1. Enter system view.

2. Enter Layer 2 Ethernet

interface view or Layer 2 aggregate interface view, or enter port group view.

3. Disable the port from

becoming a dynamic router port.

NOTE:

system-view

• Enter Layer 2 Ethernet interface view or Layer 2 aggregate interface view:

interface interface-type interface-number

• Enter port group view:

port-group manual

port-group-name

igmp-snooping router-port-deny [ vlan

vlan-list

N/A

Use either command.

By default, a port can become a dynamic router port.

]

This configuration does not affect the static router port configuration.

Configuring an IGMP snooping querier

This section describes how to configure an IGMP snooping querier.

Configuration prerequisites

Before you configure an IGMP snooping querier, complete the following tasks:

• Enable IGMP snooping in the VLAN.

• Determine the interval for sending IGMP general queries.

• Determine the IGMP last-member query interval.

• Determine the maximum response delay for IGMP general queries.

• Determine the source address of IGMP general queries.

• Determine the source address of IGMP group-specific queries.

Enabling IGMP snooping querier

In an IP multicast network that runs IGMP, a multicast router or Layer 3 multicast switch regularly sends IGMP queries. This allows all Layer 3 multicast devices to establish and maintain multicast forwarding entries for correctly forwarding multicast traffic at the network layer. This router or Layer 3 switch is called the "IGMP querier."

However, a Layer 2 multicast switch does not support IGMP and therefore cannot send general queries by default. To provide correct multicast data forwarding at the data link layer on a network without Layer 3 multicast devices, you can configure a Layer 2 switch as the IGMP snooping querier. In this way, the Layer 2 switch sends IGMP queries and establishes and maintains multicast forwarding entries.

Do not configure an IGMP snooping querier in a multicast network that runs IGMP. An IGMP snooping querier does not take part in IGMP querier elections. However, it might affect IGMP querier elections because it sends IGMP general queries with a low source IP address. For more information about IGMP querier, see "Configuring IGMP."

o enable the IGMP snooping querier in a VLAN:

Step Command Remarks

1. Enter system view.

2. Enter VLAN view.

3. Enable the IGMP snooping querier in the VLAN.

system-view

vlan-id

vlan

igmp-snooping querier

N/A

Disabled by default.

Configuring parameters for IGMP queries and responses

CAUTION:

In the configuration, make sure the IGMP general query interval is larger than the maximum response delay for IGMP general queries. Otherwise, multicast group members might be deleted by mistake.

You can modify the IGMP general query interval based on actual condition of the network.

A multicast listening host starts a timer for each multicast group that it has joined when it receives an IGMP query (general query or group-specific query). This timer is initialized to a random value ranging from 0 to the maximum response delay advertised in the IGMP query message. When the timer value decreases to 0, the host sends an IGMP report to the multicast group.

To speed up the response of hosts to IGMP queries and avoid simultaneous timer expirations causing IGMP report traffic bursts, set a proper value for the maximum response delay:

• The maximum response delay for IGMP general queries is set by the max-response-time

command.

• The maximum response delay for IGMP group-specific queries equals the IGMP last-member

query interval.

Configuring the global parameters for IGMP queries and responses

Step Command Remarks

1. Enter system view.

2. Enter IGMP-snooping view.

3. Set the maximum response

delay for IGMP general queries.

4. Set the IGMP last-member

query interval.

system-view igmp-snooping

max-response-time

last-member-query-interval

interval

interval 1 second by default.

Configuring the parameters for IGMP queries and responses in a VLAN

Step Command Remarks

1. Enter system view.

2. Enter VLAN view.

3. Set the interval for sending

IGMP general queries.

4. Set the maximum response

delay for IGMP general queries.

system-view vlan

igmp-snooping query-interval

igmp-snooping max-response-time

interval

vlan-id

interval

N/A

10 seconds by default.

N/A

60 seconds by default.

10 seconds by default.

5. Set the IGMP last-member

igmp-snooping

1 second by default.

Step Command Remarks

query interval.

last-membe

-query-interval

interval

Configuring the source IP addresses for IGMP queries

IMPORTANT:

Changing the source address for IGMP query messages might affect the IGMP querier election within the subnet.

After a switch receives an IGMP query whose source IP address is 0.0.0.0 on a port, it does not enlist that port as a dynamic router port. This might prevent multicast forwarding entries from being correctly created at the data link layer and eventually cause multicast traffic forwarding to fail. To avoid this problem, when a Layer 2 switch acts as the IGMP snooping querier, Hewlett Packard Enterprise recommends you configure a non-all-zero IP address as the source IP address of IGMP queries.

To configure source IP addresses of IGMP queries:

Step Command Remarks

1. Enter system view.

2. Enter VLAN view.

3. Configure the source IP

address for IGMP general queries.

4. Configure the source IP

address for IGMP group-specific queries.

system-view

vlan-id

current-interface

}

vlan

igmp-snooping general-query source-ip

{ ip-address |

igmp-snooping special-query source-ip

{ ip-address |

N/A

0.0.0.0 by default.

Configuring IGMP snooping proxying

This section describes how to configure IGMP snooping proxying.

Configuration prerequisites

Before you configure IGMP snooping proxying in a VLAN, complete the following tasks:

• Enable IGMP snooping in the VLAN.

• Determine the source IP address for the IGMP reports sent by the proxy.

• Determine the source IP address for the IGMP leave messages sent by the proxy.

Enabling IGMP snooping proxying

The IGMP snooping proxying function works on a per-VLAN basis. After you enable the function in a VLAN, the device works as the IGMP snooping proxy for the downstream hosts and upstream router in the VLAN.

To enable IGMP snooping proxying in a VLAN:

Step Command Remarks

1. Enter system view.

2. Enter VLAN view.

3. Enable IGMP snooping

proxying in the VLAN.

system-view

vlan-id

vlan

igmp-snooping proxying enable

N/A

Disabled by default.

Configuring the source IP addresses for the IGMP messages sent by the proxy

You can set source the IP addresses for the IGMP reports and leave messages that the IGMP snooping proxy sends on behalf of its attached hosts.

To configure the source IP addresses for the IGMP messages sent by the proxy in a VLAN:

Step Command Remarks

1. Enter system view.

2. Enter VLAN view.

3. Configure the source IP

address for the IGMP reports that the proxy sends.

4. Configure the source IP

address for the IGMP leave messages that the proxy sends.

system-view

vlan-id

current-interface

}

vlan

igmp-snooping report source-ip

{ ip-address |

igmp-snooping leave source-ip

{ ip-address |

N/A

The default is 0.0.0.0.

Configuring IGMP snooping policies

This section describes how to configure IGMP snooping policies.

Configuration prerequisites

Before you configure IGMP snooping policies, complete the following tasks:

• Enable IGMP snooping for the VLAN.

• Determine the ACL rule for multicast group filtering.

• Determine the maximum number of multicast groups that a port can join.

• Determine the 802.1p precedence for IGMP messages.

Configuring a multicast group filter

On an IGMP snooping-enabled switch, you can configure a multicast group filter to limit multicast programs available to users.

In an application, when a user requests a multicast program, the user's host initiates an IGMP report. After receiving this report message, the switch resolves the multicast group address in the report and looks up the ACL. If a match is found to permit the port that received the report to join the multicast group, the switch creates an IGMP snooping forwarding entry for the multicast group and adds the port to the forwarding entry. Otherwise, the switch drops this report message, in which case, the

multicast data for the multicast group is not sent to this port, and the user cannot retrieve the program.

Configuration guidelines

• When you configure a multicast group filter in a multicast VLAN, be sure to configure the filter in

the sub-VLANs of the multicast VLAN. Otherwise, the configuration does not take effect.

• In IGMPv3, when a host is enabled to join multiple multicast groups, the multicast group filter

cannot correctly filter multicast groups because the host that runs IGMPv3 sends multiple multicast groups that it wants to join in one membership report.

Configuration procedure

To configure a multicast group filter globally:

Step Command Remarks

1. Enter system view.

2. Enter IGMP-snooping view.

system-view igmp-snooping

N/A

3. Configure a multicast group

filter globally.

To configure a multicast group filter on a port:

group-policy

vlan-list

]

acl-number [

vlan

Step Command Remarks

1. Enter system view.

2. Enter Layer 2 Ethernet

interface view or Layer 2 aggregate interface view, or enter port group view.

3. Configure a multicast group

filter on a port.

system-view

• Enter Layer 2 Ethernet interface view or Layer 2 aggregate interface view:

interface interface-type interface-number

• Enter port group view:

port-group manual

port-group-name

igmp-snooping group-policy

acl-number [

vlan

vlan-list

]

Configuring multicast source port filtering

By default, no group filter is globally configured. That is, a host can join any valid multicast group.

N/A

Use either command.

By default, no group filter is configured on the current port. That is, the hosts on this port can join any valid multicast group.

When the multicast source port filtering feature is enabled on a port, the port can connect to only multicast receivers rather than to multicast sources, because the port blocks all multicast data packets but it permits multicast protocol packets to pass.

If this feature is disabled on a port, the port can connect to both multicast sources and multicast receivers.

Configuring multicast source port filtering globally

Step Command Remarks

1. Enter system view.

2. Enter IGMP-snooping view.

system-view igmp-snooping

N/A

Step Command Remarks

3. Enable multicast source port

filtering.

source-deny port

Configuring multicast source port filtering on a port

Step Command Remarks

1. Enter system view.

2. Enter Layer 2 Ethernet

interface view or Layer 2 aggregate interface view, or enter port group view.

3. Enable multicast source port

filtering.

system-view

• Enter Layer 2 Ethernet interface view or Layer 2 aggregate interface view:

interface interface-type interface-number

• Enter port group view:

port-group manual

port-group-name

igmp-snooping source-deny

interface-list

Disabled by default.

N/A

Use either command.

Disabled by default.

Enabling dropping unknown multicast data

Unknown multicast data refers to multicast data for which no forwarding entries exist in the IGMP

snooping forwarding table. When the switch receives such multicast traffic, one of the following occurs:

• When the function of dropping unknown multicast data is disabled, the switch floods unknown

multicast data in the VLAN that the unknown multicast data belongs to, causing network bandwidth waste and low forwarding efficiency.

• When the function of dropping unknown multicast data is enabled, the switch forwards unknown

multicast data to its router ports instead of flooding it in the VLAN. If no router ports exist, the switch drops the unknown multicast data.

Configuration guidelines

• The configurations made in IGMP snooping view are effective on all VLANs. The configurations

made in VLAN view are effective on only the ports in the current VLAN.

• If the function of dropping multicast packets is enabled globally in IGMP snooping view,

multicast packets that are sent to IGMP snooping-enabled VLANs are all dropped. The multicast packets mentioned here include both multicast data packets and protocol packets, such as PIM, OSPF, and VRRP messages.

• If the function of dropping unknown multicast data packets is enabled in VLAN view, the switch

forwards unknown multicast data packets to its router ports. In this case, if router ports do not exist, the switch drops these multicast data packets. The switch supports processing unknown multicast data packets destined for up to 2000 unknown multicast addresses at a time. The switch floods excessive unknown multicast data packets directly.

• The switch supports the function of dropping unknown multicast data packets configuring in up

to 500 VLANs.

Configuration procedure

To enable dropping unknown multicast data in a VLAN:

Step Command Remarks

1. Enter system view.

system-view

N/A

Step Command Remarks

2. Enter VLAN view.

3. Enable dropping unknown

multicast data.

vlan

igmp-snooping drop-unknown

vlan-id

Enabling IGMP report suppression

When a Layer 2 switch receives an IGMP report from a multicast group member, the switch forwards the message to the directly connected Layer 3 device. When multiple members of a multicast group are attached to the Layer 2 switch, the Layer 3 device might receive duplicate IGMP reports for the multicast group.

With the IGMP report suppression function enabled, within each query interval, the Layer 2 switch forwards only the first IGMP report for a multicast group to the Layer 3 device. It does not forward the subsequent IGMP reports for the same multicast group. This helps reduce the number of packets being transmitted over the network.

On an IGMP snooping proxy, IGMP reports for a multicast group are suppressed if a matching forwarding entry exists, whether the suppression function is enabled or not.

To enable IGMP report suppression:

N/A

Disabled by default.

Step Command Remarks

1. Enter system view.

2. Enter IGMP-snooping view.

3. Enable IGMP report

suppression.

system-view igmp-snooping

report-aggregation

N/A

Enabled by default.

Setting the maximum number of multicast groups that a port can join

You can set the maximum number of multicast groups that a port can join to regulate traffic on the port.

If the number of multicast groups the port has joined exceeds the configured maximum value, the system deletes the forwarding entries associated with the port. The hosts attached to this port need join multicast groups again until the number of multicast groups that the port joins reaches the maximum value.

• If the port has been configured as a static member port, the system applies the configurations to

the port again.

• If you have configured simulated joining on the port, the system establishes corresponding

forwarding entry for the port after receiving a report from the simulated member host.

To set the maximum number of multicast groups that a port can join:

Step Command Remarks

1. Enter system view.

2. Enter Layer 2 Ethernet

interface view or Layer 2 aggregate interface view, or enter port group view.

system-view

• Enter Layer 2 Ethernet interface view or Layer 2 aggregate interface view:

interface interface-type interface-number

N/A

Use either command.

•

Step Command Remarks

Enter port group view:

port-group manual

port-group-name

3. Set the maximum number of

multicast groups that the port can join.

igmp-snooping group-limit

vlan

[

vlan-list ]

Enabling multicast group replacement

IMPORTANT:

Be sure to configure the maximum number of multicast groups that a port can join to a value other than the default one (see "Setting the maximum number of multicast groups that a port can join") before e functionality does not take effect.

In certain situations, the number of multicast groups that the switch or a port joins might exceed the upper limit. In addition, in some specific applications, a multicast group that the switch newly joins must replace an existing multicast group automatically. A typical example is channel switching. To view a new channel, a user switches from the current multicast group to the new one.

nabling multicast group replacement. Otherwise, the multicast group replacement

limit

By default, the upper limit is 4000 for the HPE 5800 switches, and 2000 for the HPE 5820X switches.

To realize such requirements, you can enable the multicast group replacement function on the switch or on a certain port. When the number of multicast groups that the switch or on the port has joined reaches the limit, one of the following occurs:

• If the multicast group replacement feature is disabled, new IGMP reports are automatically

discarded.

• If the multicast group replacement feature is enabled, the multicast group that the switch or the

port newly joins automatically replaces an existing multicast group that has the lowest address.

Enabling multicast group replacement globally

Step Command Remarks

1. Enter system view.

2. Enter IGMP-snooping view.

3. Enable multicast group

replacement.

system-view igmp-snooping

overflow-replace [ vlan

Enabling multicast group replacement on a port

Step Command Remarks

1. Enter system view.

2. Enter Layer 2 Ethernet

interface view or Layer 2 aggregate interface view, or enter port group view.

system-view

• Enter Layer 2 Ethernet interface view or Layer 2 aggregate interface view:

interface interface-type interface-number

• Enter port group view:

port-group manual

port-group-name

N/A

vlan-list ] Disabled by default.

N/A

Use either command.

Step Command Remarks

3. Enable multicast group

replacement.

igmp-snooping overflow-replace [ vlan

vlan-list ]

Disabled by default.

Setting the 802.1p precedence for IGMP messages

You can change the 802.1p precedence of IGMP messages so that they can be assigned higher forwarding priority when congestion occurs on their outgoing ports.

Setting the 802.1p precedence for IGMP messages globally

Step Command Remarks

1. Enter system view.

2. Enter IGMP-snooping view.

3. Set the 802.1p precedence

for IGMP messages.

NOTE:

The global configuration takes effect for all VLANs.

system-view igmp-snooping

dot1p-priority

priority-number

N/A

The default 802.1p precedence for IGMP messages is 0.

Setting the 802.1p precedence for IGMP messages in a VLAN

Step Command Remarks

1. Enter system view.

2. Enter VLAN view.

3. Set the 802.1p precedence

for IGMP messages in the VLAN.

system-view vlan

vlan-id N/A

igmp-snooping dot1p-priority

priority-number

Configuring a multicast user control policy

Multicast user control policies are configured on access switches to allow only authorized users to receive requested multicast traffic data. This helps restrict users from ordering certain multicast-on-demand programs.

A multicast user control policy is functionally similar to a multicast group filter. A control policy can control both multicast joining and leaving of users based on authentication and authorization. However, multicast group filter is configured on a port to control only multicast joining but not leaving of users without authentication or authorization.

In practice, a device first needs to perform authentication (for example, 802.1X authentication) for the connected hosts through a RADIUS server. Then, the device uses the configured multicast user control policy to perform multicast access control for authenticated users as follows:

• After receiving an IGMP report from a host, the access switch matches the multicast group

address and multicast source address carried in the report against the configured policies. If a match is found, the host is allowed to join the multicast group. Otherwise, the join report is dropped by the access switch.

N/A

The default 802.1p precedence for IGMP messages is 0.

• After receiving an IGMP leave message from a host, the access switch matches the multicast

group address and source address with the policies. If a match is found, the host is allowed to leave the group. Otherwise, the leave message is dropped by the access switch.

To configure a multicast user control policy:

Step Command Remarks

1. Enter system view.

system-view

N/A

2. Create a user profile and

enter its view.

3. Configure a multicast user

control policy.

4. Return to system view.

5. Enable the created user

profile.

user-profile

igmp-snooping access-policy

acl-number

quit

user-profile

profile-name

enable

For more information about this

command, see Security Command Reference.

No policy is configured by default. A host can join or leave a valid multicast group at any time.

N/A

Disabled by default.

For more information about this

command, see Security Command Reference.

Enabling the IGMP snooping host tracking function

With the IGMP snooping host tracking function, the switch can record the information of the member hosts that are receiving multicast traffic. The information includes the host IP address, running duration, and timeout time. You can monitor and manage the member hosts according to the recorded information.

Enabling the IGMP snooping host tracking function globally

Step Command Remarks

1. Enter system view.

2. Enter IGMP-snooping view.

3. Enable the IGMP snooping

host tracking function globally.

system-view igmp-snooping

host-tracking

N/A

Disabled by default.

Enabling the IGMP snooping host tracking function in a VLAN

Step Command Remarks

1. Enter system view.

2. Enter VLAN view.

3. Enable the IGMP snooping

host tracking function in the VLAN.

system-view

vlan-id

vlan

igmp-snooping host-tracking

N/A

Disabled by default.

Setting the DSCP value for IGMP messages

This configuration applies to only the IGMP messages that the local switch generates when the switch or its port acts as a member host, rather than those forwarded ones.

To set the DSCP value for IGMP messages:

Step Command Remarks

1. Enter system view.

2. Enter IGMP-snooping view.

3. Set the DSCP value for

IGMP messages

system-view igmp-snooping

dscp

dscp-value

N/A

By default, the DSCP value in IGMP messages is 48.

Displaying and maintaining IGMP snooping

Task Command Remarks

Display IGMP snooping group information.

Display information about the hosts tracked by IGMP snooping.

Display static multicast MAC address entries.

Display statistics for the IGMP messages learned through IGMP snooping.

Remove dynamic group entries for IGMP snooping groups.

display igmp-snooping group

vlan-id ] [

begin

{

regular-expression ]

display igmp-snooping host vlan group

source-address ] [

begin

{

regular-expression ]

display mac-address

vlan-id ] | [

count

[

regular-expression ]

display igmp-snooping statistics

exclude

reset igmp-snooping group

all

slot

slot-number ] ] [

exclude

group-address [

exclude

multicast

begin

] ] [ | {

include

vlan

} [

vlan-id ]

include

source

slot

slot-number ] [

include

[ mac-address [

vlan

] [

exclude

} regular-expression ]

[ [

verbose

}

vlan-id ]

include

{ group-address

vlan

] [ |

vlan-id

vlan

begin

[ | {

}

Available in any view.

Available in user view.

This command works only on an IGMP snooping-enabled VLAN, but not in a VLAN with IGMP enabled on its VLAN interface.

This command cannot remove the static group entries of IGMP snooping groups.

Clear statistics for the IGMP messages learned through IGMP snooping.

reset igmp-snooping statistics

Available in user view.

IGMP snooping configuration examples

This section describes details about IGMP snooping configuration Examples.

Group policy and simulated joining configuration example (in a VLAN)

Network requirements

As shown in Figure 14, IGMPv2 runs on Router A, IGMPv2 snooping runs on Switch A, and Router A acts as the IGMP querier on the subnet.

Configure a group policy and simulated joining to meet the following requirements:

• Host A and Host B can receive multicast traffic addressed to multicast group 224.1.1.1 only.

• Multicast data for group 224.1.1.1 can be forwarded through GigabitEthernet 1/0/3 and

GigabitEthernet 1/0/4 of Switch A even if Host A and Host B accidentally, temporarily stop receiving multicast data. Switch A drops unknown multicast data and does not broadcast the data to the VLAN where Switch A resides.

Figure 14 Network diagram

Configuration procedure

1. Assign an IP address and subnet mask to each interface according to Figure 14. (Details not

shown.)

2. On Router A, enable IP multicast routing, enable IGMP on GigabitEthernet 1/0/1, and enable

PIM-DM on each interface.

<RouterA> system-view [RouterA] multicast routing-enable [RouterA] interface gigabitethernet 1/0/1 [RouterA-GigabitEthernet1/0/1] igmp enable [RouterA-GigabitEthernet1/0/1] pim dm [RouterA-GigabitEthernet1/0/1] quit [RouterA] interface gigabitethernet 1/0/2 [RouterA-GigabitEthernet1/0/2] pim dm [RouterA-GigabitEthernet1/0/2] quit

3. Configure Switch A:

# Enable IGMP snooping globally.

<SwitchA> system-view

[SwitchA] igmp-snooping [SwitchA-igmp-snooping] quit

# Create VLAN 100, assign GigabitEthernet 1/0/1 through GigabitEthernet 1/0/4 to this VLAN, and enable IGMP snooping and the function of dropping unknown multicast traffic in the VLAN.

[SwitchA] vlan 100 [SwitchA-vlan100] port gigabitethernet 1/0/1 to gigabitethernet 1/0/4 [SwitchA-vlan100] igmp-snooping enable [SwitchA-vlan100] igmp-snooping drop-unknown [SwitchA-vlan100] quit

# Configure a multicast group filter so that the hosts in VLAN 100 can join only the multicast group 224.1.1.1.

[SwitchA] acl number 2001 [SwitchA-acl-basic-2001] rule permit source 224.1.1.1 0 [SwitchA-acl-basic-2001] quit [SwitchA] igmp-snooping [SwitchA-igmp-snooping] group-policy 2001 vlan 100 [SwitchA-igmp-snooping] quit

# Configure GigabitEthernet 1/0/3 and GigabitEthernet 1/0/4 as simulated hosts for multicast group 224.1.1.1.

[SwitchA] interface gigabitethernet 1/0/3 [SwitchA-GigabitEthernet1/0/3] igmp-snooping host-join 224.1.1.1 vlan 100 [SwitchA-GigabitEthernet1/0/3] quit [SwitchA] interface gigabitethernet 1/0/4 [SwitchA-GigabitEthernet1/0/4] igmp-snooping host-join 224.1.1.1 vlan 100 [SwitchA-GigabitEthernet1/0/4] quit

Verifying the configuration

# Display detailed IGMP snooping group information in VLAN 100 on Switch A.

[SwitchA] display igmp-snooping group vlan 100 verbose Total 1 IP Group(s). Total 1 IP Source(s). Total 1 MAC Group(s).

Port flags: D-Dynamic port, S-Static port, C-Copy port, P-PIM port Subvlan flags: R-Real VLAN, C-Copy VLAN Vlan(id):100. Total 1 IP Group(s). Total 1 IP Source(s). Total 1 MAC Group(s). Router port(s):total 1 port(s). GE1/0/1 (D) ( 00:01:30 ) IP group(s):the following ip group(s) match to one mac group. IP group address:224.1.1.1 (0.0.0.0, 224.1.1.1): Attribute: Host Port Host port(s):total 2 port(s). GE1/0/3 (D) ( 00:03:23 ) GE1/0/4 (D) ( 00:04:10 ) MAC group(s):

MAC group address:0100-5e01-0101 Host port(s):total 2 port(s). GE1/0/3 GE1/0/4

The output shows that GigabitEthernet 1/0/3 and GigabitEthernet 1/0/4 on Switch A have joined the multicast group 224.1.1.1.

Static port configuration example (in a VLAN)

Network requirements

As shown in Figure 15:

• IGMPv2 runs on Router A, and IGMPv2 snooping runs on Switch A, Switch B, and Switch C,

with Router A acting as the IGMP querier.

• Host A and host C are permanent receivers of multicast group 224.1.1.1.

Perform the following tasks to meet the requirements:

• To enhance the reliability of multicast traffic transmission, configure GigabitEthernet 1/0/3 and

GigabitEthernet 1/0/5 on Switch C as static member ports for multicast group 224.1.1.1.

• Suppose the STP runs on the network. To avoid data loops, the forwarding path from Switch A

to Switch C is blocked under normal conditions. Multicast traffic flows to the receivers attached to Switch C only along the path of Switch A—Switch B—Switch C. To make sure multicast traffic can flow to the receivers nearly uninterruptedly along the path of Switch A—Switch C, configure GigabitEthernet 1/0/3 on Switch A as a static router port.

NOTE:

If no static router port is configured, when the path of Switch A—Switch B—Switch C is blocked, at least one IGMP query-response cycle must be completed before the multicast data can flow to the receivers along the new path of Switch A—Switch C. Namely, multicast delivery is interrupted during this process.

For more information about STP, see Layer 2—LAN Switching Configuration Guide.

Figure 15 Network diagram

Configuration procedure

1. Assign an IP address and subnet mask to each interface according to Figure 15. (Details not

shown.)

2. On Router A, enable IP multicast routing, enable IGMP on GigabitEthernet 1/0/1, and enable

PIM-DM on each interface.

3. Configure Switch A:

# Enable IGMP snooping globally.

<SwitchA> system-view [SwitchA] igmp-snooping [SwitchA-igmp-snooping] quit

# Create VLAN 100, assign GigabitEthernet 1/0/1 through GigabitEthernet 1/0/3 to this VLAN, and enable IGMP snooping in the VLAN.

[SwitchA] vlan 100 [SwitchA-vlan100] port gigabitethernet 1/0/1 to gigabitethernet 1/0/3 [SwitchA-vlan100] igmp-snooping enable [SwitchA-vlan100] quit

# Configure GigabitEthernet 1/0/3 to be a static router port.

[SwitchA] interface gigabitethernet 1/0/3 [SwitchA-GigabitEthernet1/0/3] igmp-snooping static-router-port vlan 100

[SwitchA-GigabitEthernet1/0/3] quit

4. Configure Switch B:

# Enable IGMP snooping globally.

<SwitchB> system-view [SwitchB] igmp-snooping [SwitchB-igmp-snooping] quit

# Create VLAN 100, assign GigabitEthernet 1/0/1 and GigabitEthernet 1/0/2 to this VLAN, and enable IGMP snooping in the VLAN.

[SwitchB] vlan 100 [SwitchB-vlan100] port gigabitethernet 1/0/1 gigabitethernet 1/0/2 [SwitchB-vlan100] igmp-snooping enable [SwitchB-vlan100] quit

5. Configure Switch C:

# Enable IGMP snooping globally.

<SwitchC> system-view [SwitchC] igmp-snooping [SwitchC-igmp-snooping] quit

# Create VLAN 100, assign GigabitEthernet 1/0/1 through GigabitEthernet 1/0/5 to this VLAN, and enable IGMP snooping in the VLAN.

[SwitchC] vlan 100 [SwitchC-vlan100] port gigabitethernet 1/0/1 to gigabitethernet 1/0/5 [SwitchC-vlan100] igmp-snooping enable [SwitchC-vlan100] quit

# Configure GigabitEthernet 1/0/3 and GigabitEthernet 1/0/5 as static member ports for multicast group 224.1.1.1.

[SwitchC] interface GigabitEthernet 1/0/3 [SwitchC-GigabitEthernet1/0/3] igmp-snooping static-group 224.1.1.1 vlan 100 [SwitchC-GigabitEthernet1/0/3] quit [SwitchC] interface GigabitEthernet 1/0/5 [SwitchC-GigabitEthernet1/0/5] igmp-snooping static-group 224.1.1.1 vlan 100 [SwitchC-GigabitEthernet1/0/5] quit

Verifying the configuration

# Display detailed IGMP snooping group information in VLAN 100 on Switch A.

[SwitchA] display igmp-snooping group vlan 100 verbose Total 1 IP Group(s). Total 1 IP Source(s). Total 1 MAC Group(s).

IP group address:224.1.1.1 (0.0.0.0, 224.1.1.1): Attribute: Host Port Host port(s):total 1 port. GE1/0/2 (D) ( 00:03:23 ) MAC group(s): MAC group address:0100-5e01-0101 Host port(s):total 1 port. GE1/0/2

The output shows that GigabitEthernet 1/0/3 of Switch A has become a static router port.

# Display detailed IGMP snooping group information in VLAN 100 on Switch C.

[SwitchC] display igmp-snooping group vlan 100 verbose Total 1 IP Group(s). Total 1 IP Source(s). Total 1 MAC Group(s).

Port flags: D-Dynamic port, S-Static port, C-Copy port, P-PIM port Subvlan flags: R-Real VLAN, C-Copy VLAN Vlan(id):100. Total 1 IP Group(s). Total 1 IP Source(s). Total 1 MAC Group(s). Router port(s):total 1 port(s). GE1/0/2 (D) ( 00:01:23 ) IP group(s):the following ip group(s) match to one mac group. IP group address:224.1.1.1 (0.0.0.0, 224.1.1.1): Attribute: Host Port Host port(s):total 2 port(s). GE1/0/3 (S) GE1/0/5 (S) MAC group(s): MAC group address:0100-5e01-0101 Host port(s):total 2 port(s). GE1/0/3 GE1/0/5

The output shows that GigabitEthernet 1/0/3 and GigabitEthernet 1/0/5 on Switch C have become static member ports for multicast group 224.1.1.1.

IGMP snooping querier configuration example

Network requirements

As shown in Figure 16:

• In a Layer 2–only network environment, two multicast sources Source 1 and Source 2 send

multicast data to multicast groups 224.1.1.1 and 225.1.1.1, respectively.

• Host A and Host C are receivers of multicast group 224.1.1.1, and Host B and Host D are

receivers of multicast group 225.1.1.1.

• IGMPv2 runs on all receivers, and IGMPv2 snooping runs on all switches.

• Switch A, which is close to the multicast sources, is chosen as the IGMP snooping querier.

Perform the following tasks to meet the requirements:

• To prevent flooding of unknown multicast traffic within the VLAN, be sure to configure all

switches to drop unknown multicast data packets.

• A switch does not enlist a port that has received an IGMP query with a source IP address of

0.0.0.0 (default) as a dynamic router port. To ensure normal creation of Layer 2 multicast forwarding entries, you must configure a non-all-zero IP address as the source IP address of IGMP queries.

Figure 16 Network diagram

Configuration procedure

1. Configure switch A:

# Enable IGMP snooping globally.

<SwitchA> system-view [SwitchA] igmp-snooping [SwitchA-igmp-snooping] quit

# Create VLAN 100, and assign GigabitEthernet 1/0/1 through GigabitEthernet 1/0/3 to the VLAN.

[SwitchA] vlan 100 [SwitchA-vlan100] port gigabitethernet 1/0/1 to gigabitethernet 1/0/3

# Enable IGMP snooping and the function of dropping unknown multicast traffic in VLAN 100.

[SwitchA-vlan100] igmp-snooping enable [SwitchA-vlan100] igmp-snooping drop-unknown

# Enable the IGMP snooping querier function in VLAN 100.

[SwitchA-vlan100] igmp-snooping querier

# Set the source IP address of IGMP general queries and group-specific queries to 192.168.1.1 in VLAN 100.

[SwitchA-vlan100] igmp-snooping general-query source-ip 192.168.1.1 [SwitchA-vlan100] igmp-snooping special-query source-ip 192.168.1.1 [SwitchA-vlan100] quit

2. Configure Switch B:

# Enable IGMP snooping globally.

<SwitchB> system-view [SwitchB] igmp-snooping [SwitchB-igmp-snooping] quit

# Create VLAN 100, and assign GigabitEthernet 1/0/1 through GigabitEthernet 1/0/4 to the VLAN.

[SwitchB] vlan 100 [SwitchB-vlan100] port gigabitethernet 1/0/1 to gigabitethernet 1/0/4

# Enable IGMP snooping and the function of dropping unknown multicast traffic in VLAN 100.

[SwitchB-vlan100] igmp-snooping enable [SwitchB-vlan100] igmp-snooping drop-unknown [SwitchB-vlan100] quit

3. Configure Switch C in the same way as you configure Switch B. (Details not shown.)

4. Configure Switch D in the same way as you configure Switch B. (Details not shown.)

Verifying the configuration

Verify that all switches but the querier can receive IGMP general queries after the IGMP snooping querier starts to work. This example uses Switch B.

# Display statistics for the IGMP messages on Switch B.

[SwitchB] display igmp-snooping statistics Received IGMP general queries:3. Received IGMPv1 reports:0. Received IGMPv2 reports:12. Received IGMP leaves:0. Received IGMPv2 specific queries:0. Sent IGMPv2 specific queries:0. Received IGMPv3 reports:0. Received IGMPv3 reports with right and wrong records:0. Received IGMPv3 specific queries:0. Received IGMPv3 specific sg queries:0. Sent IGMPv3 specific queries:0. Sent IGMPv3 specific sg queries:0. Received error IGMP messages:0.

IGMP snooping proxying configuration example

Network requirements

As shown in Figure 17, IGMPv2 runs on Router A, and IGMPv2 snooping runs on Switch A. Router A serves as an IGMP querier.

Configure IGMP snooping proxying on Switch A to meet the following requirements:

• Switch A can forward IGMP reports and leave messages on behalf of attached hosts.

• Switch A can respond to IGMP queries from Router A and forward the queries to the hosts on

behalf of Router A.

Figure 17 Network diagram

Receiver

Host A

Source

GE1/0/2

1.1.1.2/24

1.1.1.1/24

Router A

IGMP querier

Configuration procedure

1. Assign an IP address and subnet mask to each interface according to Figure 17. (Details not

shown.)

2. On Router A, enable IP multicast routing globally, enable IGMP on GigabitEthernet 1/0/1, and

enable PIM-DM on each interface.

3. Configure Switch A:

# Enable IGMP snooping globally.

<SwitchA> system-view [SwitchA] igmp-snooping [SwitchA-igmp-snooping] quit

# Create VLAN 100, assign ports GigabitEthernet 1/0/1 through GigabitEthernet 1/0/4 to this VLAN, and enable IGMP snooping and IGMP snooping proxying in the VLAN.

[SwitchA] vlan 100 [SwitchA-vlan100] port gigabitethernet 1/0/1 to gigabitethernet 1/0/4 [SwitchA-vlan100] igmp-snooping enable [SwitchA-vlan100] igmp-snooping proxying enable [SwitchA-vlan100] quit

GE1/0/1

10.1.1.1/24

GE1/0/1

Switch A

Proxy & Querier

GE1/0/4

GE1/0/3

GE1/0/2

Receiver

Host B

Host C

VLAN 100

Verifying the configuration

After the configuration is completed, Host A and Host B send IGMP join messages for group

224.1.1.1. Receiving the messages, Switch A sends a join message for the group out of GigabitEthernet 1/0/1 (a router port) to Router A.

# Display information about the IGMP snooping groups on Switch A.

[SwitchA] display igmp-snooping group Total 1 IP Group(s). Total 1 IP Source(s). Total 1 MAC Group(s).

Port flags: D-Dynamic port, S-Static port, C-Copy port, P-PIM port Subvlan flags: R-Real VLAN, C-Copy VLAN Vlan(id):100. Total 1 IP Group(s). Total 1 IP Source(s). Total 1 MAC Group(s). Router port(s):total 1 port. GE1/0/1 (D) IP group(s):the following ip group(s) match to one mac group. IP group address:224.1.1.1 (0.0.0.0, 224.1.1.1): Host port(s):total 2 port. GE1/0/3 (D) GE1/0/4 (D) MAC group(s): MAC group address:0100-5e01-0101 Host port(s):total 2 port. GE1/0/3 GE1/0/4

# Display information about the IGMP multicast groups on Router A.

[RouterA] display igmp group Total 1 IGMP Group(s). Interface group report information of VPN-Instance: public net GigabitEthernet1/0/1(10.1.1.1): Total 1 IGMP Group reported Group Address Last Reporter Uptime Expires

224.1.1.1 0.0.0.0 00:00:06 00:02:04

When Host A leaves the multicast group, it sends an IGMP leave message to Switch A. Receiving the message, Switch A removes port GigabitEthernet 1/0/4 from the member port list of the forwarding entry for the group; however, it does not remove the group or forward the leave message

to Router A because Host B is still in the group. Use the display igmp-snooping group command

to display information about IGMP snooping groups. For example:

# Display information about the IGMP snooping groups on Switch A.

[SwitchA] display igmp-snooping group Total 1 IP Group(s). Total 1 IP Source(s). Total 1 MAC Group(s). Port flags: D-Dynamic port, S-Static port, C-Copy port, P-PIM port Subvlan flags: R-Real VLAN, C-Copy VLAN Vlan(id):100. Total 1 IP Group(s). Total 1 IP Source(s).

Total 1 MAC Group(s). Router port(s):total 1 port. GE1/0/1 (D) IP group(s):the following ip group(s) match to one mac group. IP group address:224.1.1.1 (0.0.0.0, 224.1.1.1): Host port(s):total 1 port. GE1/0/3 (D) MAC group(s): MAC group address:0100-5e01-0101 Host port(s):total 1 port. GE1/0/3

Multicast source and user control policy configuration example

Network requirements

As shown in Figure 18, Switch A is a Layer-3 switch. IGMPv2 runs on Switch A and IGMPv2 snooping runs on Switch B. Multicast sources and hosts run 802.1X client.

Perform the following tasks to meet the requirements:

• To block multicast traffic from Source 2 to group 224.1.1.1, configure a multicast source control

policy on Switch A.

• To make sure Host A can join or leave only multicast group 224.1.1.1, configure a multicast user

control policy on Switch B.

Figure 18 Network diagram

Configuration procedures

1. Assign an IP address and subnet mask to each interface according to Figure 18. (Details not

shown.)

2. Configure Switch A:

# Create VLAN 101 through VLAN 104, and assign GigabitEthernet 1/0/1 through GigabitEthernet 1/0/4 to the four VLANs respectively.

<SwitchA> system-view [SwitchA] vlan 101 [SwitchA-vlan101] port gigabitethernet 1/0/1 [SwitchA-vlan101] quit [SwitchA] vlan 102 [SwitchA-vlan102] port gigabitethernet 1/0/2 [SwitchA-vlan102] quit [SwitchA] vlan 103 [SwitchA-vlan103] port gigabitethernet 1/0/3 [SwitchA-vlan103] quit [SwitchA] vlan 104 [SwitchA-vlan104] port gigabitethernet 1/0/4 [SwitchA-vlan104] quit

# Enable IP multicast routing, enable PIM-DM on VLAN-interface 101, VLAN-interface 102 and VLAN-interface 104, and enable IGMP on VLAN-interface 104.

[SwitchA] multicast routing-enable [SwitchA] interface vlan-interface 101 [SwitchA-Vlan-interface101] pim dm [SwitchA-Vlan-interface101] quit [SwitchA] interface vlan-interface 102 [SwitchA-Vlan-interface102] pim dm [SwitchA-Vlan-interface102] quit [SwitchA] interface vlan-interface 104 [SwitchA-Vlan-interface104] pim dm [SwitchA-Vlan-interface104] igmp enable [SwitchA-Vlan-interface104] quit

# Create QoS policy policy1 to block multicast flows from Source 2 to 224.1.1.1.

[SwitchA] acl number 3001 [SwitchA-acl-adv-3001] rule permit udp source 2.1.1.1 0 destination 224.1.1.1 0 [SwitchA-acl-adv-3001] quit [SwitchA] traffic classifier classifier1 [SwitchA-classifier-classifier1] if-match acl 3001 [SwitchA-classifier-classifier1] quit [SwitchA] traffic behavior behavior1 [SwitchA-behavior-behavior1] filter deny [SwitchA-behavior-behavior1] quit [SwitchA] qos policy policy1 [SwitchA-qospolicy-policy1] classifier classifier1 behavior behavior1 [SwitchA-qospolicy-policy1] quit

# Create user profile profile1, apply QoS policy policy1 to the inbound direction in user profile

view, and enable the user profile.

[SwitchA] user-profile profile1 [SwitchA-user-profile-profile1] qos apply policy policy1 inbound [SwitchA-user-profile-profile1] quit [SwitchA] user-profile profile1 enable

# Create RADIUS scheme scheme1, set the service type for the RADIUS server to extended,

and specify the IP addresses of the primary authentication/authorization server and accounting server as 3.1.1.1. Then, set the shared keys to 123321, and specify that no domain name is carried in a username sent to the RADIUS server.

[SwitchA] radius scheme scheme1 [SwitchA-radius-scheme1] server-type extended [SwitchA-radius-scheme1] primary authentication 3.1.1.1 [SwitchA-radius-scheme1] key authentication 123321 [SwitchA-radius-scheme1] primary accounting 3.1.1.1 [SwitchA-radius-scheme1] key accounting 123321 [SwitchA-radius-scheme1] user-name-format without-domain [SwitchA-radius-scheme1] quit

# Create ISP domain domain1, reference scheme1 for the authentication, authorization, and accounting of LAN users, and specify domain1 as the default ISP domain.

[SwitchA] domain domain1 [SwitchA-isp-domian1] authentication lan-access radius-scheme scheme1 [SwitchA-isp-domian1] authorization lan-access radius-scheme scheme1 [SwitchA-isp-domian1] accounting lan-access radius-scheme scheme1 [SwitchA-isp-domian1] quit [SwitchA] domain default enable domain1

# Globally enable 802.1X, and enable it on GigabitEthernet 1/0/1 and GigabitEthernet 1/0/2 respectively.

[SwitchA] dot1x [SwitchA] interface gigabitethernet 1/0/1 [SwitchA-GigabitEthernet1/0/1] dot1x [SwitchA-GigabitEthernet1/0/1] quit [SwitchA] interface gigabitethernet 1/0/2 [SwitchA-GigabitEthernet1/0/2] dot1x [SwitchA-GigabitEthernet1/0/2] quit

3. Configure Switch B:

# Globally enable IGMP snooping.

<SwitchB> system-view [SwitchB] igmp-snooping [SwitchB-igmp-snooping] quit

# Create VLAN 104, assign GigabitEthernet 1/0/1 through GigabitEthernet 1/0/3 to this VLAN, and enable IGMP snooping in this VLAN.

[SwitchB] vlan 104 [SwitchB-vlan104] port gigabitethernet 1/0/1 to gigabitethernet 1/0/3 [SwitchB-vlan104] igmp-snooping enable [SwitchB-vlan104] quit

# Create a user profile profile2 to allow users to join or leave only multicast group 224.1.1.1,

and enable the user profile.

[SwitchB] acl number 2001 [SwitchB-acl-basic-2001] rule permit source 224.1.1.1 0 [SwitchB-acl-basic-2001] quit [SwitchB] user-profile profile2 [SwitchB-user-profile-profile2] igmp-snooping access-policy 2001 [SwitchB-user-profile-profile2] quit [SwitchB] user-profile profile2 enable

# Create a RADIUS scheme scheme2, set the service type for the RADIUS server to extended,

and specify the IP addresses of the primary authentication/authorization server and accounting server as 3.1.1.1. Then, set the shared keys to 321123, and specify that a username sent to the RADIUS server carry no domain name.

[SwitchB] radius scheme scheme2 [SwitchB-radius-scheme2] server-type extended [SwitchB-radius-scheme2] primary authentication 3.1.1.1 [SwitchB-radius-scheme2] key authentication 321123 [SwitchB-radius-scheme2] primary accounting 3.1.1.1 [SwitchB-radius-scheme2] key accounting 321123 [SwitchB-radius-scheme2] user-name-format without-domain [SwitchB-radius-scheme2] quit

# Create an ISP domain domain2, reference scheme2 for the authentication, authorization, and accounting of LAN users, and specify domain2 as the default ISP domain.

[SwitchB] domain domain2 [SwitchB-isp-domian2] authentication lan-access radius-scheme scheme2 [SwitchB-isp-domian2] authorization lan-access radius-scheme scheme2 [SwitchB-isp-domian2] accounting lan-access radius-scheme scheme2 [SwitchB-isp-domian2] quit [SwitchB] domain default enable domain2

# Globally enable 802.1X, and enable it on GigabitEthernet 1/0/2 and GigabitEthernet 1/0/3 respectively.

[SwitchB] dot1x [SwitchB] interface gigabitethernet 1/0/2 [SwitchB-GigabitEthernet1/0/2] dot1x [SwitchB-GigabitEthernet1/0/2] quit [SwitchB] interface gigabitethernet 1/0/3 [SwitchB-GigabitEthernet1/0/3] dot1x [SwitchB-GigabitEthernet1/0/3] quit

4. On the RADIUS server, configure the parameters related to Switch A and Switch B.

For more information, see the configuration guide of the RADIUS server.

Verifying the configuration

1. Verify that Host A can join only the multicast group 224.1.1.1.

# Verify that the two multicast sources and hosts pass the 802.1X authentication. (Details not shown.)

# Send multicast traffic from Source 1 and Source 2 to the multicast group 224.1.1.1 and

224.1.1.2, respectively. (Details not shown.)

# Send an IGMP report from Host A to join the multicast groups 224.1.1.1 and 224.1.1.2. (Details not shown.)

# Display information about the IGMP snooping groups in VLAN 104 on Switch B.

[SwitchB] display igmp-snooping group vlan 100 verbose Total 1 IP Group(s). Total 1 IP Source(s). Total 1 MAC Group(s).

GE1/0/1 (D) ( 00:01:30 ) IP group(s):the following ip group(s) match to one mac group. IP group address:224.1.1.1 (0.0.0.0, 224.1.1.1): Attribute: Host Port Host port(s):total 1 port(s). GE1/0/3 (D) ( 00:04:10 ) MAC group(s): MAC group address:0100-5e01-0101 Host port(s):total 1 port(s). GE1/0/3

The output shows that GigabitEthernet 1/0/3 on Switch B has joined 224.1.1.1 but not 224.1.1.2. This means that the user control policy on Switch B has taken effect.

2. Verify that Host A can receive only the multicast traffic from Source 1 to the multicast group

224.1.1.1.

# Send multicast traffic from Source 2 to the multicast group 224.1.1.1. (Details not shown.)

# Display information about the multicast group 224.1.1.1 on Switch A.

[SwitchA] display multicast forwarding-table 224.1.1.1 Multicast Forwarding Table of VPN-Instance: public net

Total 1 entry

Total 1 entry matched

00001. (1.1.1.1, 224.1.1.1) MID: 0, Flags: 0x0:0 Uptime: 00:08:32, Timeout in: 00:03:26 Incoming interface: Vlan-interface101 List of 1 outgoing interfaces: 1: Vlan-interface104 Matched 19648 packets(20512512 bytes), Wrong If 0 packets Forwarded 19648 packets(20512512 bytes)

The output shows that Switch A maintains a multicast forwarding entry for multicast packets from Source 1 to 224.1.1.1. No forwarding entry exists for packets from Source 2 to 224.1.1.1, which means that multicast packets from Source 2 are blocked.

Troubleshooting IGMP snooping

This section describes details about troubleshooting IGMP snooping.

Layer 2 multicast forwarding cannot function

Symptom

Layer 2 multicast forwarding cannot function.

Analysis

IGMP snooping is not enabled.

Solution

1. Use the display current-configuration command to display the running status of IGMP

snooping.

2. If IGMP snooping is not enabled, use the igmp-snooping command in system view to enable IGMP snooping globally. Then, use the igmp-snooping enable command in VLAN view to

enable IGMP snooping for the VLAN.

3. If IGMP snooping is enabled globally but not enabled for the VLAN, use the igmp-snooping enable command in VLAN view to enable IGMP snooping for the VLAN.

Configured multicast group policy fails to take effect

Symptom

Although a multicast group policy has been configured to allow hosts to join specific multicast groups, the hosts can still receive multicast data addressed to other multicast groups.

Analysis

• The ACL rule is incorrectly configured.

• The multicast group policy is not correctly applied.

• The function of dropping unknown multicast data is not enabled, so unknown multicast data is

flooded.

Solution

1. Use the display acl command to verify that the ACL rule conforms to the multicast group policy

to be implemented.

2. Use the display this command in IGMP-snooping view or in the corresponding interface view to verify that the correct multicast group policy has been applied. If not, use the group-policy or

igmp-snooping group-policy command to apply the correct multicast group policy.

3. Use the display current-configuration command to verify that the function of dropping unknown multicast data is enabled. If not, use the drop-unknown or igmp-snooping drop-unknown command to enable the function of dropping unknown multicast data.

Appendix

This section describes details about processing multicast protocol messages.

Processing of multicast protocol messages

With Layer 3 multicast routing enabled, an IGMP snooping-enabled switch processes multicast protocol messages differently under different conditions, as follows:

• If only IGMP is enabled on the switch, or if both IGMP and PIM are enabled on the switch, the

switch does the following:

{ Maintains dynamic member ports or dynamic router ports according to IGMP packets

{ Maintains dynamic router ports according to PIM hello packets

• If only PIM is enabled on the switch, the following occur:

{ The switch broadcasts IGMP messages as unknown messages in the VLAN.

{ After receiving a PIM hello message, the switch maintains the corresponding dynamic

router port.

• If IGMP is disabled on the switch, one of the following occurs:

{ If PIM is disabled, the switch deletes all its dynamic member ports and dynamic router ports.

{ If PIM is enabled, the switch deletes only its dynamic member ports but not its dynamic

router ports.

NOTE:

On a switch with Layer-3 multicast routing enabled, use the display igmp group port-info

command to display Layer-2 port information.

• If PIM is disabled on the switch, one of the following occurs:

{ If IGMP is disabled, the switch deletes all its dynamic router ports.

{ If IGMP is enabled, the switch maintains all its dynamic member ports and dynamic router

ports.

Configuring PIM snooping

This chapter describes PIM snooping, how to configure PIM snooping, configuration examples, and troubleshooting methods.

Overview

PIM snooping runs on Layer 2 devices. It examines the received PIM messages to determine the ports that are interested in the multicast data addressed to a multicast group , and adds the ports to the multicast forwarding entry for the multicast group, so that the multicast data can be forwarded to only the ports that are interested in the data.

Figure 19 Multicast packet transmission without or with PIM snooping

Source 1

PIM

router 1

PIM

router 3

Multicast packet transmission

when only IGMP snooping runs

Source 2

Layer 2 switch

PIM

router 2

PIM

router 4

Multicast packet transmission when

IGMP snooping and PIM snooping both run

Source 1 Source 2

PIM

router 1

Layer 2 switch

PIM

router 3

PIM

router 2

PIM

router 4

Receiver 1 Receiver 2

Multicast packets (S1, G1) Join message (S1, G1)

Multicast packets (S2, G2) Join message (S2, G2)

Receiver 1 Receiver 2

As shown in Figure 19, Source 1 sends multicast data to multicast group G1, and Source 2 sends multicast data to multicast group G2. Receiver 1 belongs to G1 and Receiver 2 belongs to G2. The Layer 2 switch's interfaces that connect to the PIM-capable routers are in the same VLAN.

• When the Layer 2 switch runs only IGMP snooping, it does the following actions:

{ Maintains the router ports according to the received PIM hello messages that PIM-capable

routers send.

{ Floods all other types of received PIM messages in the VLAN.

{ Forwards all multicast data to all router ports in the VLAN.

Each PIM-capable router in the VLAN, whether interested in the multicast data or not, can receive all multicast data and all PIM messages except PIM hello messages.

• When the Layer 2 switch runs both IGMP snooping and PIM snooping, it does the following

actions:

{ Examines the received PIM messages to determine which PIM-capable routers are

interested in the multicast data addressed to a multicast group.

{ Adds only the ports that connect to these routers to the multicast forwarding entry for the

multicast group.

{ Forwards PIM messages and multicast data to only the routers that are interested in the

data. This saves network bandwidth.

For more information about IGMP snooping and the router port, see "Configuring IGMP snooping."

For mo

re information about PIM, see "Configuring PIM."

Configuring PIM snooping

When you configure PIM snooping, follow these guidelines:

• After you enable PIM snooping for a VLAN, PIM snooping works only on the member interfaces

of the VLAN.

• PIM snooping does not work in the sub-VLANs of a multicast VLAN. For more information about

multicast VLAN, see "Configuring multicast VLANs."

• In a network

message no more than the path MTU on the PIM-enabled edge router on the receiver side. For more information about the join/prune messages, see "Configuring PIM."

To configure PIM snooping:

Step Command Remarks

1. Enter system view.

2. Enable IGMP snooping globally and

enter IGMP-snooping view.

3. Return to system view.

4. Enter VLAN view.

with PIM snooping enabled switches, configure the size of each join/prune

system-view

igmp-snooping

quit

vlan

vlan-id

N/A

Disabled by default.

N/A

5. Enable IGMP snooping in the VLAN.

6. Enable PIM snooping in the VLAN.

igmp-snooping enable pim-snooping enable

Disabled by default.

Displaying and maintaining PIM snooping

Task Command Remarks

Display PIM snooping neighbor information.

display pim-snooping neighbor

vlan-id ] [

slot

slot-number ] ] [

{

vlan

[ [

begin

Available in any view.

Task Command Remarks

exclude

include

} regular-expression ]

Display PIM snooping routing entries.

Display statistics for PIM messages learned through PIM snooping.

display pim-snooping routing-table

vlan-id ] [

exclude

slot

slot-number ] ] [

include

} regular-expression ]

{

begin

display pim-snooping statistics [ | exclude

include

} regular-expression ]

[ [

{

vlan

begin

Available in any view.

Clear statistics for PIM messages learned through PIM

reset pim-snooping statistics

Available in user view.

snooping.

PIM snooping configuration example (in a VLAN)

Network requirements

As shown in Figure 20:

• Source 1 sends multicast data to multicast group 224.1.1.1, and Source 2 sends multicast data

to multicast group 225.1.1.1.

• Receiver 1 belongs to multicast group 224.1.1.1, and Receiver 2 belongs to multicast group

225.1.1.1.

• Router C and Router D run IGMP on GigabitEthernet 1/0/1.

Router A, Router B, Router C, and Router D run PIM-SM, and GigabitEthernet 1/0/2 on Router A acts as a C-BSR and C-RP.

Configure IGMP snooping and PIM snooping on Switch A so that Switch A forwards PIM messages and multicast data to only the routers that are interested in the multicast data.

Figure 20 Network diagram

Source 1

GE1/0/1

1.1.1.100/24

Source 2

2.1.1.100/24

1.1.1.1/24

GE1/0/1

2.1.1.1/24

Configuration procedure

1. Assign an IP address and subnet mask to each interface according to Figure 20. (Details not

shown.)

2. On Router A. enable IP multicast routing, enable PIM-SM on each interface, and configure

interface GigabitEthernet 1/0/2 as a C-BSR and C-RP.

<RouterA> system-view

Router A

GE1/0/2

10.1.1.1/24

GE1/0/1

GE1/0/2

10.1.1.2/24

Router B Router D

10.1.1.3/24

Switch A

10.1.1.4/24

Router C

GE1/0/2

GE1/0/3

GE1/0/4

GE1/0/2

GE1/0/1

3.1.1.1/24

GE1/0/1

4.1.1.1/24

Receiver 1

3.1.1.100/24

Receiver 2

4.1.1.100/24

[RouterA] multicast routing-enable [RouterA] interface gigabitethernet 1/0/1 [RouterA-GigabitEthernet1/0/1] pim sm [RouterA-GigabitEthernet1/0/1] quit [RouterA] interface gigabitethernet 1/0/2 [RouterA-GigabitEthernet1/0/2] pim sm [RouterA-GigabitEthernet1/0/2] quit [RouterA] pim [RouterA-pim] c-bsr gigabitethernet 1/0/2 [RouterA-pim] c-rp gigabitethernet 1/0/2

3. On Router B, enable IP multicast routing, and enable PIM-SM on each interface.

<RouterB> system-view [RouterB] multicast routing-enable [RouterB] interface gigabitethernet 1/0/1 [RouterB-GigabitEthernet1/0/1] pim sm [RouterB-GigabitEthernet1/0/1] quit [RouterB] interface gigabitethernet 1/0/2 [RouterB-GigabitEthernet1/0/2] pim sm

4. On Router C, enable IP multicast routing, enable PIM-SM on each interface, and enable IGMP

on GigabitEthernet 1/0/1.

<RouterC> system-view [RouterC] multicast routing-enable [RouterC] interface gigabitethernet 1/0/1 [RouterC-GigabitEthernet1/0/1] pim sm [RouterC-GigabitEthernet1/0/1] igmp enable [RouterC-GigabitEthernet1/0/1] quit [RouterC] interface gigabitethernet 1/0/2 [RouterC-GigabitEthernet1/0/2] pim sm

5. Configure Router D in the same way as you configure Router C. (Details not shown.)

6. Configure Switch A:

# Enable IGMP snooping globally.

<SwitchA> system-view [SwitchA] igmp-snooping [SwitchA-igmp-snooping] quit

# Create VLAN 100, assign GigabitEthernet 1/0/1 through GigabitEthernet 1/0/4 to this VLAN, and enable IGMP snooping and PIM snooping in the VLAN.

[SwitchA] vlan 100 [SwitchA-vlan100] port gigabitethernet 1/0/1 to gigabitethernet 1/0/4 [SwitchA-vlan100] igmp-snooping enable [SwitchA-vlan100] pim-snooping enable [SwitchA-vlan100] quit

Verifying the configuration

# On Switch A, display the PIM snooping neighbor information of VLAN 100.

[SwitchA] display pim-snooping neighbor vlan 100 Total number of neighbors: 4

VLAN ID: 100 Total number of neighbors: 4

Neighbor Port Expires Option Flags

10.1.1.1 GE1/0/1 02:02:23 LAN Prune Delay

10.1.1.2 GE1/0/2 03:00:05 LAN Prune Delay

10.1.1.3 GE1/0/3 02:22:13 LAN Prune Delay

10.1.1.4 GE1/0/4 03:07:22 LAN Prune Delay

The output shows that Router A, Router B, Router C, and Router D are PIM snooping neighbors.

# On Switch A, display the PIM snooping routing information of VLAN 100.

[SwitchA] display pim-snooping routing-table vlan 100 slot 1 Total 2 entry(ies) FSM Flag: NI-no info, J-join, PP-prune pending

VLAN ID: 100 Total 2 entry(ies) (*, 224.1.1.1) Upstream neighbor: 10.1.1.1 Upstream port: GE1/0/1 Total number of downstream ports: 1 1: GE1/0/3 Expires: 00:03:01, FSM: J (*, 225.1.1.1) Upstream neighbor: 10.1.1.2 Upstream port: GE1/0/2 Total number of downstream ports: 1 1: GE1/0/4 Expires: 00:03:11, FSM: J

The output shows that Switch A will forward the multicast data intended for multicast group 224.1.1.1 to only Router C, and forward the multicast data intended for multicast group 225.1.1.1 to only Router D.

Troubleshooting PIM snooping

This section describes details about troubleshooting PIM snooping.

PIM snooping does not work

Symptom

PIM snooping does not work.

Analysis

IGMP snooping or PIM snooping is not enabled.

Solution

1. Use the display current-configuration command to verify the status of IGMP snooping and

PIM snooping.

2. If IGMP snooping is not enabled, enter system view and use the igmp-snooping command to enable IGMP snooping globally. Then, enter VLAN view and use the igmp-snooping enable and pim-snooping enable commands to enable IGMP snooping and PIM snooping for the

VLAN.

3. If PIM snooping is not enabled, enter VLAN view and use the pim-snooping enable command

to enable PIM snooping for the VLAN.

Some downstream PIM-capable routers cannot receive multicast data

Symptom

In a network with fragmented join/prune messages, some downstream PIM-capable routers cannot receive multicast data.

Analysis

PIM snooping cannot reassemble messages, and it cannot maintain the status of downstream routers that the join/prune message fragments carry. To ensure normal operation of the system, PIM snooping must broadcast join/prune message fragments in the VLAN. However, if the VLAN has a PIM-capable router that has the join suppression function enabled, the broadcast join/prune message fragments might suppress the join messages of other PIM-capable routers in the VLAN. As a result, some PIM-capable routers cannot receive the multicast data destined for a specific multicast group because their join messages are suppressed. To solve this problem, disable the join suppression function on all PIM-capable routers that connect to the PIM snooping-capable switch in the VLAN.

Solution

1. Use the pim hello-option neighbor-tracking command to enable the neighbor tracking

function on the interfaces of PIM routers that connect to the PIM snooping-capable switch.

2. If a PIM-capable router cannot be enabled with the neighbor tracking function, you have to

disable PIM snooping on the switch.

Configuring multicast VLANs

This chapter describes multicast VLAN, how to configure multicast VLAN, and configuration examples.

Overview

As shown in Figure 21, Host A, Host B, and Host C reside in different VLANs and require the same multicast programs-on-demand service. Router A (Layer 3 device) must forward a separate copy of the multicast data to Switch A (Layer 2 device). This occupies large bandwidth and increases the burden on the Layer 3 device.

Figure 21 Multicast transmission without the multicast VLAN feature

Multicast packets

VLAN 2

VLAN 3

VLAN 4

Source

Router A

IGMP querier

Switch A

The multicast VLAN feature on the Layer 2 device is the solution to this issue. After the multicast VLAN is configured on Switch A, Router A sends only one copy of the multicast data to the multicast VLAN on Switch A. This saves network bandwidth and lessens the burden on the Layer 3 device.

The multicast VLAN feature can be implemented in a sub-VLAN-based multicast VLAN and a port-based multicast VLAN.

Sub-VLAN-based multicast VLAN

VLAN 2

Receiver

Host A

VLAN 3

Receiver

Host B

VLAN 4

Receiver

Host C

As shown in Figure 22:

• Host A, Host B, and Host C are in VLAN 2 through VLAN 4, respectively.

• On Switch A, VLAN 10 is a multicast VLAN.

VLAN 2 through VLAN 4 are sub-VLANs of VLAN 10.

IGMP snooping is enabled for the multicast VLAN.

Figure 22 Sub-VLAN-based multicast VLAN

IGMP snooping manages router ports in the multicast VLAN and member ports in the sub-VLANs. When Router A receives the multicast data from the source, it sends only one copy of the multicast data to Switch A in the multicast VLAN. Switch A distributes a separate copy of the data to each sub-VLAN of the multicast VLAN.

Port-based multicast VLAN

As shown in Figure 23,:

• Host A, Host B, and Host C are in VLAN 2 through VLAN 4, respectively.

• On Switch A, VLAN 10 is configured as a multicast VLAN.

All user ports (ports with attached hosts) are hybrid ports and are assigned to VLAN 10.

IGMP snooping is enabled for the multicast VLAN and VLAN 2 through VLAN 4.

Figure 23 Port-based multicast VLAN

Multicast packets

VLAN 10 (Multicast VLAN)

GE1/0/1

Source

Router A

IGMP querier

IGMP snooping manages the router ports and member ports in the multicast VLAN. When Switch A receives an IGMP message on a user port, it tags the message with the multicast VLAN ID and sends it to the IGMP querier. When Router A receives the multicast data, it sends only one copy of

Switch A

GE1/0/2

GE1/0/3

GE1/0/4

VLAN 2

Receiver

Host A

VLAN 3

Receiver

Host B

VLAN 4

Receiver

Host C

the multicast data to Switch A in the multicast VLAN. Switch A distributes the data to all member ports in the multicast VLAN.

For more information about IGMP snooping, router ports, and member ports, see "Configuring IGMP

sno

oping."

For more information about VLAN tags, see Layer 2—LAN Switching Configuration Guide.

Multicast VLAN configuration task list

Task Remarks

Configuring a sub-VLAN-based multicast VLAN

Configuring a port-based multicast VLAN

Setting the maximum number of forwarding entries for multicast VLANs Optional.

NOTE:

If you have configured both a sub-VLAN-based multicast VLAN and a port-based multicast VLAN on a device, the port-based multicast VLAN configuration is given preference.

Configuring user port attributes

Configuring multicast VLAN ports

Required.

Use either approach.

Configuring a sub-VLAN-based multicast VLAN

This section describes how to configure a sub-VLAN-based multicast VLAN.

Configuration prerequisites

Before you configure a sub-VLAN-based multicast VLAN, complete the following tasks:

• Create VLANs as required.

• Enable IGMP snooping in the VLAN to be configured as a multicast VLAN.

Configuration guidelines

• You cannot configure a multicast VLAN on a device with IP multicast routing enabled.

• The VLAN to be configured as a multicast VLAN must exist.

• The VLANs to be configured as sub-VLANs of the multicast VLAN must exist and must not be

multicast VLANs or sub-VLANs of any other multicast VLAN.

• The total number of sub-VLANs of a multicast VLAN must not exceed the maximum number the

system can support. This maximum number varies with device models.

Configuration procedure

In this approach, you configure a VLAN as a multicast VLAN, and configure VLANs that contain receivers as sub-VLANs of the multicast VLAN.

To configure a sub-VLAN-based multicast VLAN:

Step Command Remarks

1. Enter system view.

2. Configure the specified

VLAN as a multicast VLAN and enter multicast VLAN view.

3. Configure the specified

VLANs as sub-VLANs of the multicast VLAN.

system-view

multicast-vlan

subvlan

vlan-list

vlan-id

N/A

By default, a VLAN is not a multicast VLAN.

By default, a multicast VLAN has no sub-VLANs.

Configuring a port-based multicast VLAN

When you configure a port-based multicast VLAN, you must configure the attributes of each user port and then assign the ports to the multicast VLAN.

A user port can be configured as a multicast VLAN port only if it is an Ethernet port or a Layer 2 aggregate interface.

The configurations made in Ethernet interface view or Layer 2 aggregate interface view, are effective on only the current port. The configurations made in port group view are effective on all ports in the current port group.

Configuration prerequisites

Before you configure a port-based multicast VLAN, complete the following tasks:

• Create VLANs as required.

• Enable IGMP snooping in the VLAN to be configured as a multicast VLAN.

• Enable IGMP snooping in all user VLANs.

Configuring user port attributes

Configure a user ports as a hybrid port to permit VLAN-tagged packets, and configure the PVID of the user port to be the VLAN it belongs to.

Configure the user port to permit the multicast VLAN packets and untag the packets. Thus, after receiving the multicast VLAN-tagged packets from the upstream device, the Layer 2 device untags the multicast packets and forwards them to its downstream device.

For more information about the port link-type, port hybrid pvid vlan, and port hybrid vlan commands, see Layer 2—LAN Switching Command Reference.

To configure user port attributes:

Step Command Remarks

1. Enter system view.

system-view

N/A

Step Command Remarks

• Enter Layer 2 Ethernet interface view or Layer 2 aggregate interface view:

2. Enter proper view.

interface interface-type

interface-number

• Enter port group view:

port-group manual

port-group-name

Use either command.

3. Configure the user port link

type as hybrid.

4. Specify the PVID of the

current user port to be the VLAN it belongs to.

5. Configure the current user

port to permit the multicast VLAN and untag the packets.

port link-type hybrid

port hybrid pvid vlan

port hybrid vlan untagged

vlan-id-list

vlan-id

Configuring multicast VLAN ports

Configure a VLAN as a multicast VLAN, and assign user ports to it. You can do it by either adding the user ports in the multicast VLAN or specifying the multicast VLAN on the user ports. These two methods provide the same result.

Configuration guidelines

• You cannot configure a multicast VLAN on a device with multicast routing enabled.

• The VLAN to be configured as a multicast VLAN must exist.

• A port must belong to a single multicast VLAN.

Configuring multicast VLAN ports in multicast VLAN view

By default, the port link type is access.

By default, the PVID of a hybrid port is VLAN 1.

By default, a hybrid port permits only VLAN 1.

Step Command Remarks

1. Enter system view.

2. Configure the specified VLAN

as a multicast VLAN and enter multicast VLAN view.

3. Assign ports to the multicast

VLAN.

system-view

multicast-vlan

port

interface-list

vlan-id

N/A

By default, a VLAN is not a multicast VLAN.

By default, a multicast VLAN has no ports.

Configuring multicast VLAN ports in interface view or port group view

Step Command Remarks

1. Enter system view.

2. Configure the specified

VLAN as a multicast VLAN and enter multicast VLAN view.

3. Return to system view.

system-view

multicast-vlan

quit

vlan-id

N/A

A VLAN is not a multicast VLAN by default.

N/A

Step Command Remarks

• Enter Layer 2 Ethernet interface view or Layer 2 aggregate interface view:

4. Enter proper view.

5. Assign the current port to the

multicast VLAN.

interface interface-type interface-number

• Enter port group view:

port-group manual

port-group-name

port multicast-vlan

vlan-id

Use either command.

By default, a user port does not belong to any multicast VLAN.

Setting the maximum number of forwarding entries for multicast VLANs

You can configure the maximum number of entries in the IGMP snooping forwarding table of a multicast VLAN. If the number of existing entries in the IGMP snooping forwarding table for the multicast VLAN is larger than the limit that you set, the system informs you to remove excessive entries. In this case, the system does not automatically remove any existing entries or create new entries.

To configure the maximum number of entries in the forwarding table:

Step Command Remarks

1. Enter system view.

2. Configure the maximum

number of forwarding entries in a multicast VLAN.

system-view

multicast-vlan entry-limit

limit

N/A

By default, the upper limit is 4000 for the HPE 5800 switches, and 2000 for the HPE 5820X switches.

Displaying and maintaining a multicast VLAN

Task Command Remarks

Display information about a multicast VLAN.

display multicast-vlan

begin

[ | {

regular-expression ]

exclude

[ vlan-id ]

include

}

Available in any view.

Multicast VLAN configuration examples

This section describes details about multicast VLAN configuration examples.

Sub-VLAN-based multicast VLAN configuration example

Network requirements

As shown in Figure 24:

• IGMPv2 runs on Router A, and IGMPv2 snooping runs on Switch A, Switch B, and Switch C.

Router A acts as the IGMP querier.

• The multicast source sends multicast data to the multicast group 224.1.1.1. Host A, Host B,

Host C, and Host D are receivers of the multicast data. The hosts belong to VLAN 2 through VLAN 5 respectively.

Configure the sub-VLAN-based multicast VLAN feature on Switch A to meet the following requirements:

• Router A sends the multicast data to Switch A through the multicast VLAN.

• Switch A forwards the multicast data to the receivers in different VLANs.

Figure 24 Network diagram

Configuration procedure

1. Assign an IP address and subnet mask to each interface according to Figure 24. (Details not

shown.)

2. On Router A, enable IP multicast routing, enable PIM-DM on each interface, and enable IGMP

on the host-side interface GigabitEthernet 1/0/2.

<RouterA> system-view [RouterA] multicast routing-enable [RouterA] interface gigabitethernet 1/0/1 [RouterA-GigabitEthernet1/0/1] pim dm [RouterA-GigabitEthernet1/0/1] quit [RouterA] interface gigabitethernet 1/0/2 [RouterA-GigabitEthernet1/0/2] pim dm [RouterA-GigabitEthernet1/0/2] igmp enable

3. Configure Switch A:

# Enable IGMP snooping globally.

<SwitchA> system-view [SwitchA] igmp-snooping [SwitchA-igmp-snooping] quit

# Create VLAN 2 through VLAN 5.

[SwitchA] vlan 2 to 5

# Configure GigabitEthernet 1/0/2 as a trunk port, and assign it to VLAN 2 and VLAN 3.

[SwitchA] interface gigabitethernet 1/0/2 [SwitchA-GigabitEthernet1/0/2] port link-type trunk [SwitchA-GigabitEthernet1/0/2] port trunk permit vlan 2 3 [SwitchA-GigabitEthernet1/0/2] quit

# Configure GigabitEthernet 1/0/3 as a trunk port, and assign it to VLAN 4 and VLAN 5.

[SwitchA] interface gigabitethernet 1/0/3 [SwitchA-GigabitEthernet1/0/3] port link-type trunk [SwitchA-GigabitEthernet1/0/3] port trunk permit vlan 4 5 [SwitchA-GigabitEthernet1/0/3] quit

# Create VLAN 10, assign GigabitEthernet 1/0/1 to this VLAN, and enable IGMP snooping in the VLAN.

[SwitchA] vlan 10 [SwitchA-vlan10] port gigabitethernet 1/0/1 [SwitchA-vlan10] igmp-snooping enable [SwitchA-vlan10] quit

# Configure VLAN 10 as a multicast VLAN, and configure VLAN 2 through VLAN 5 as its sub-VLANs.

[SwitchA] multicast-vlan 10 [SwitchA-mvlan-10] subvlan 2 to 5 [SwitchA-mvlan-10] quit

4. Configure Switch B:

# Enable IGMP snooping globally.

<SwitchB> system-view [SwitchB] igmp-snooping [SwitchB-igmp-snooping] quit

# Create VLAN 2, assign GigabitEthernet 1/0/2 to VLAN 2, and enable IGMP snooping in the VLAN.

[SwitchB] vlan 2 [SwitchB-vlan2] port gigabitethernet 1/0/2 [SwitchB-vlan2] igmp-snooping enable [SwitchB-vlan2] quit

# Create VLAN 3, assign GigabitEthernet 1/0/3 to VLAN 3, and enable IGMP snooping in the VLAN.

[SwitchB] vlan 3 [SwitchB-vlan3] port gigabitethernet 1/0/3 [SwitchB-vlan3] igmp-snooping enable [SwitchB-vlan3] quit

# Configure GigabitEthernet 1/0/1 as a trunk port, and assign it to VLAN 2 and VLAN 3.

[SwitchB] interface gigabitethernet 1/0/1 [SwitchB-GigabitEthernet1/0/1] port link-type trunk [SwitchB-GigabitEthernet1/0/1] port trunk permit vlan 2 3

5. Configure Switch C in the same way as you configure Switch B. (Details not shown.)

Verifying the configuration

# Display information about the multicast VLAN.

[SwitchA] display multicast-vlan Total 1 multicast-vlan(s)

Multicast vlan 10 subvlan list: vlan 2-5 port list: no port

# Display IGMP snooping multicast group information on Switch A.

[SwitchA] display igmp-snooping group Total 5 IP Group(s). Total 5 IP Source(s). Total 5 MAC Group(s).

Port flags: D-Dynamic port, S-Static port, C-Copy port, P-PIM port Subvlan flags: R-Real VLAN, C-Copy VLAN Vlan(id):2. Total 1 IP Group(s). Total 1 IP Source(s). Total 1 MAC Group(s). Router port(s):total 0 port(s). IP group(s):the following ip group(s) match to one mac group. IP group address:224.1.1.1 (0.0.0.0, 224.1.1.1): Host port(s):total 1 port(s). GE1/0/2 (D) MAC group(s): MAC group address:0100-5e01-0101 Host port(s):total 1 port(s). GE1/0/2

Vlan(id):3. Total 1 IP Group(s). Total 1 IP Source(s). Total 1 MAC Group(s). Router port(s):total 0 port(s). IP group(s):the following ip group(s) match to one mac group. IP group address:224.1.1.1 (0.0.0.0, 224.1.1.1): Host port(s):total 1 port(s). GE1/0/2 (D) MAC group(s): MAC group address:0100-5e01-0101 Host port(s):total 1 port(s). GE1/0/2

Vlan(id):4. Total 1 IP Group(s). Total 1 IP Source(s). Total 1 MAC Group(s).

Router port(s):total 0 port(s). IP group(s):the following ip group(s) match to one mac group. IP group address:224.1.1.1 (0.0.0.0, 224.1.1.1): Host port(s):total 1 port(s). GE1/0/3 (D) MAC group(s): MAC group address:0100-5e01-0101 Host port(s):total 1 port(s). GE1/0/3

Vlan(id):5. Total 1 IP Group(s). Total 1 IP Source(s). Total 1 MAC Group(s). Router port(s):total 0 port(s). IP group(s):the following ip group(s) match to one mac group. IP group address:224.1.1.1 (0.0.0.0, 224.1.1.1): Host port(s):total 1 port(s). GE1/0/3 (D) MAC group(s): MAC group address:0100-5e01-0101 Host port(s):total 1 port(s). GE1/0/3

Vlan(id):10. Total 1 IP Group(s). Total 1 IP Source(s). Total 1 MAC Group(s). Router port(s):total 1 port(s). GE1/0/1 (D) IP group(s):the following ip group(s) match to one mac group. IP group address:224.1.1.1 (0.0.0.0, 224.1.1.1): Host port(s):total 0 port(s). MAC group(s): MAC group address:0100-5e01-0101 Host port(s):total 0 port(s).

The output shows that IGMP snooping maintains the router port in the multicast VLAN (VLAN 10) and the member ports in the sub-VLANs (VLAN 2 through VLAN 5).

Port-based multicast VLAN configuration example

Network requirements

As shown in Figure 25:

• IGMPv2 runs on Router A. IGMPv2 snooping runs on Switch A. Router A acts as the IGMP

querier.

• The multicast source sends multicast data to the multicast group 224.1.1.1. Host A, Host B, and

Host C are receivers of the multicast data, and the hosts belong to VLAN 2 through VLAN 4 respectively.

Configure the port-based multicast VLAN feature on Switch A to meet the following requirements:

• Router A sends multicast data to Switch A through the multicast VLAN.

• Switch A forwards the multicast data to the receivers in different VLANs.

Figure 25 Network diagram

Configuration procedure

1. Assign an IP address and subnet mask to each interface according to Figure 25. (Details not

shown.)

2. On Router A, enable IP multicast routing, enable PIM-DM on each interface, and enable IGMP

on the host-side interface GigabitEthernet 1/0/2.

3. Configure Switch A:

# Enable IGMP snooping globally.

<SwitchA> system-view [SwitchA] igmp-snooping [SwitchA-igmp-snooping] quit

# Create VLAN 10, assign GigabitEthernet 1/0/1 to VLAN 10, and enable IGMP snooping in this VLAN.

[SwitchA] vlan 10 [SwitchA-vlan10] port gigabitethernet 1/0/1 [SwitchA-vlan10] igmp-snooping enable

[SwitchA-vlan10] quit

# Create VLAN 2, and enable IGMP snooping in the VLAN.

[SwitchA] vlan 2 [SwitchA-vlan2] igmp-snooping enable [SwitchA-vlan2] quit

# Create VLAN 3 and enable IGMP snooping in the VLAN. (Details not shown.)

# Create VLAN 4 and enable IGMP snooping in the VLAN. (Details not shown.)

# Configure GigabitEthernet 1/0/2 as a hybrid port, and configure VLAN 2 as the PVID of the hybrid port. Then, assign GigabitEthernet 1/0/2 as an untagged VLAN member.

[SwitchA] interface gigabitethernet 1/0/2 [SwitchA-GigabitEthernet1/0/2] port link-type hybrid [SwitchA-GigabitEthernet1/0/2] port hybrid pvid vlan 2 [SwitchA-GigabitEthernet1/0/2] port hybrid vlan 2 untagged [SwitchA-GigabitEthernet1/0/2] port hybrid vlan 10 untagged [SwitchA-GigabitEthernet1/0/2] quit

# Configure GigabitEthernet 1/0/3 and GigabitEthernet 1/0/4 in the same way. (Details not shown.)

# Configure VLAN 10 as a multicast VLAN.

[SwitchA] multicast-vlan 10

# Assign GigabitEthernet 1/0/2 and GigabitEthernet 1/0/3 to VLAN 10.

[SwitchA-mvlan-10] port gigabitethernet 1/0/2 to gigabitethernet 1/0/3 [SwitchA-mvlan-10] quit

# Assign GigabitEthernet 1/0/4 to VLAN 10.

[SwitchA] interface gigabitethernet 1/0/4 [SwitchA-GigabitEthernet1/0/4] port multicast-vlan 10 [SwitchA-GigabitEthernet1/0/4] quit

Verifying the configuration

# Display multicast VLAN information on Switch A.

[SwitchA] display multicast-vlan Total 1 multicast-vlan(s)

Multicast vlan 10 subvlan list: no subvlan port list: GE1/0/2 GE1/0/3 GE1/0/4

# Display IGMP snooping multicast group information on Switch A.

[SwitchA] display igmp-snooping group Total 1 IP Group(s). Total 1 IP Source(s). Total 1 MAC Group(s).

Port flags: D-Dynamic port, S-Static port, C-Copy port, P-PIM port Subvlan flags: R-Real VLAN, C-Copy VLAN Vlan(id):10. Total 1 IP Group(s). Total 1 IP Source(s).

Total 1 MAC Group(s). Router port(s):total 1 port(s). GE1/0/1 (D) IP group(s):the following ip group(s) match to one mac group. IP group address:224.1.1.1 (0.0.0.0, 224.1.1.1): Host port(s):total 3 port(s). GE1/0/2 (D) GE1/0/3 (D) GE1/0/4 (D) MAC group(s): MAC group address:0100-5e01-0101 Host port(s):total 3 port(s). GE1/0/2 GE1/0/3 GE1/0/4

The output shows that IGMP snooping is maintaining the router ports and member ports in VLAN 10.

Configuring multicast routing and forwarding

This chapter describes multicast routing and forwarding, how to configure multicast routing and forwarding, configuration examples, and troubleshooting methods.

Hardware compatibility

To use GRE related features on the switches, you must install SD or EB cards.

Overview

In multicast implementations, the following types of tables implement multicast routing and forwarding:

• Multicast routing table of a multicast routing protocol—Each multicast routing protocol has

its own multicast routing table, such as the PIM routing table.

• General multicast routing table—The multicast routing information of different multicast

routing protocols forms a general multicast routing table.

• Multicast forwarding table—The multicast forwarding table helps guide the forwarding of

multicast packets.

A multicast routing table consists of a set of (S, G) entries. Each entry contains the routing information for delivering multicast data from a multicast source to a multicast group. If a router supports multiple multicast protocols, its multicast routing table contains all routes generated by multiple protocols. The router chooses the optimal route from the multicast routing table based on the configured multicast routing and forwarding policy and adds the route entry to its multicast forwarding table.

The term "interface" in this chapter collectively refers to Layer 3 interfaces, including VLAN interfaces and Layer 3 Ethernet interfaces. You can set an Ethernet port as a Layer 3 interface by

using the port link-mode route command (see Layer 2—LAN Switching Configuration Guide).

RPF check mechanism

A multicast routing protocol relies on the existing unicast routes, MBGP routes, or static multicast routes in creating multicast routing entries. When creating multicast routing table entries, a multicast routing protocol uses the RPF check mechanism to ensure multicast data delivery along the correct paths.

In addition, the RPF check mechanism also helps avoid data loops.

RPF check process

A multicast routing protocol uses the following tables to perform the RPF check:

• Unicast routing table—Contains unicast routing information.

• MBGP multicast routing table—Contains MBGP multicast routing information.

• Static multicast routing table—Contains static multicast routes.

MBGP multicast routing table and static multicast routing table are used for RPF check rather than

multicast routing.

When a router performs an RPF check, it looks up its unicast routing table, MBGP routing table, and static multicast routing table.

The specific process of RPF check is as follows:

1. The router chooses an optimal route from the unicast routing table, the MBGP routing table, and

the static multicast routing table, respectively:

{ The router searches its unicast routing table and automatically chooses an optimal unicast

route to the packet source address. The outgoing interface of the route is the RPF interface and the next hop is the RPF neighbor. The router considers the path of the packet that the RPF interface receives from the RPF neighbor as the shortest path that leads back to the source.

{ The router searches its MBGP routing table and automatically chooses an optimal MBGP

route to the packet source address. The outgoing interface of the route is the RPF interface and the next hop is the RPF neighbor.

{ The router searches its static multicast routing table and automatically chooses an optimal

static multicast route to the packet source address. The route explicitly defines the RPF interface and the RPF neighbor.

2. The router selects one of the optimal routes as the RPF route according to the following

principles:

{ If the router uses the longest match principle, it selects the longest matching route as the

RPF route. If the routes have the same mask, the router selects the route that has the highest priority as the RPF route. If the routes have the same priority, the router selects a route as the RPF route in the order of static multicast route, MBGP route, and unicast route.

{ If the router does not use the longest match principle, it selects the route that has the

highest priority as the RPF route. If the routes have the same priority, the router selects a route as the RPF route in the order of static multicast route, MBGP route, and unicast route.

The packet source can mean different things in different situations:

• For a packet traveling along the SPT from the multicast source to the receivers or the RP, the

packet source for RPF check is the multicast source.

• For a packet traveling along the RPT from the RP to the receivers, the packet source for RPF

check is the RP.

• For a packet traveling along the source-side RPT from the multicast source to the RP, the

packet source for RPF check is the RP.

• For a bootstrap message from the bootstrap router (BSR), the packet source for RPF check is

the BSR.

For more information about the concepts of SPT, RPT, source-side RPT, RP, and BSR, see "Configuring PIM."

RPF check implementation in multicast

Implementing an RPF check on each received multicast packet would bring a big burden to the router. The use of a multicast forwarding table is the solution to this issue. When the router creates a multicast forwarding entry for a multicast packet, it sets the RPF interface of the packet as the incoming interface of the forwarding entry. After the outer receives a multicast packet from an interface, it searches its multicast forwarding table for a matching entry:

• If no match is found, the router first determines the RPF route back to the packet source. Then,

it creates a forwarding entry with the RPF interface as the incoming interface and makes the following judgments:

{ If the receiving interface is the RPF interface, the RPF check succeeds and the router

forwards the packet to all outgoing interfaces.

{ If the receiving interface is not the RPF interface, the RPF check fails and the router

discards the packet.

• If a match is found and the receiving interface is the incoming interface of the entry, the router

forwards the packet to all outgoing interfaces.

• If a match is found but the receiving interface is not the incoming interface of the entry, the

router determines the RPF route back to the packet source. Then, it makes the following judgments:

{ If the RPF interface of the RPF route is the incoming interface, it means that the forwarding

entry is correct but the packet traveled along a wrong path. The router discards the packet.

{ If the RPF interface is not the incoming interface, it means that the forwarding entry has

expired. The router replaces the incoming interface with the RPF interface and matches the receiving interface against the RPF interface. If the receiving interface is the RPF interface, the router forwards the packet to all outgoing interfaces. Otherwise, it discards the packet.

As shown in Figure 26, u

nicast routes are available in the network, MBGP is not configured, and no static multicast routes have been configured on Switch C. Multicast packets travel along the SPT from the multicast source to the receivers. The multicast forwarding table on Switch C contains the (S, G) entry, with VLAN-interface 20 as the incoming interface.

Figure 26 RPF check process

IP Routing Table on Switch C

Destination/Mask

192.168.0.0/24

Source

192.168.0.1/24

Multicast packets

Interface

Vlan-int20

Switch A

Vlan-int20

Switch B

Vlan-int10

Switch C

Receiver

• If a multicast packet arrives at Switch C on VLAN-interface 20, Switch C forwards the packet to

all outgoing interfaces.

• If a multicast packet arrives at VLAN-interface 10, Switch C performs an RPF check on the

packet. Switch C searches its unicast routing table and finds that the outgoing interface to the source (the RPF interface) is VLAN-interface 20. It means that the (S, G) entry is correct but the packet traveled along a wrong path. The packet fails the RPF check, and Switch C discards the packet.

Static multicast routes

A static multicast route is an important basis for RPF check. Depending on the application environment, a static multicast route can change an RPF route and create an RPF route.

Changing an RPF route

Typically, the topology structure of a multicast network is the same as that of a unicast network, and multicast traffic follows the same transmission path as unicast traffic does. You can configure a static multicast route for a multicast source to change the RPF route. This allows the router to create a transmission path for multicast traffic that is different from the transmission path for unicast traffic.

Figure 27 Changing an RPF route

As shown in Figure 27, when no static multicast route is configured, Switch C's RPF neighbor on the path back to the source is Switch A. The multicast information from the source travels along the path from Switch A to Switch C, which is the unicast route between the two switches. You can configure a static multicast route on Switch C, and specify Switch B as Switch C's RPF neighbor on the path back to the source. Then, multicast information from the source travels from Switch A to Switch B, and then to Switch C.

Creating an RPF route

When a unicast route is blocked, multicast traffic forwarding might be stopped due to lack of an RPF route. By configuring a static multicast route for a given multicast source, you can create an RPF route so that a multicast routing entry is created to guide multicast traffic forwarding, regardless of whether a unicast route is available.

Figure 28 Creating an RPF route

Multicast Routing Table Static on Switch C

Source/Mask

192.168.0.0/24

Multicast Routing Table Static on Switch D

Source/Mask

192.168.0.0/24

Source

192.168.0.1/24

Interface

Vlan-int10

Interface

Vlan-int20

Switch A Switch B Switch C

RPF neighbor/Mask

1.1.1.1/24

RPF neighbor/Mask

2.2.2.2/24

RIP domain

Vlan-int10

1.1.1.1/24

OSPF domain

Vlan-int10

1.1.1.2/24

Switch D

Vlan-int20

2.2.2.1/24

Vlan-int20

2.2.2.2/24

Receiver

Multicast packets Multicast static route

As shown in Figure 28, the RIP domain and the OSPF domain are unicast isolated from each other. When no static multicast route is configured, the receivers in the OSPF domain cannot receive the multicast packets that the multicast source sent in the RIP domain. You can configure a static

multicast route on Switch C and Switch D, and specify Switch B and Switch C as the RPF neighbors of each other. Then, the receivers can receive multicast data that the multicast source sent.

NOTE:

• Static multicast routes only affect RPF checks but cannot guide multicast forwarding.

static multicast route is effective only on the multicast router on which it is configured, and is not

• advertised throughout the network or redistributed to other routers.

Multicast forwarding across unicast subnets

Multicast data travels hop by hop along the forwarding tree from a multicast source to the multicast receivers. However, some devices might not support multicast protocols. When the multicast traffic is forwarded to a next-hop device that does not support IP multicast, the forwarding path is blocked. In this case, you can enable multicast traffic forwarding across the unicast subnet, where the non-multicast-capable device resides, by establishing a GRE tunnel or an IPv4 over IPv4 tunnel between the devices at both ends of the unicast subnet.

For more information about GRE and tunneling, see Layer 3—IP Services Configuration Guide.

Figure 29 Multicast data transmission through a GRE tunnel

As shown in Figure 29, a GRE tunnel is established between Switch A and Switch B. Switch A encapsulates multicast data in unicast IP packets. Unicast switches then forward the unicast IP packets to Switch B across the GRE tunnel. When Switch B receives the unicast IP packets, it strips off the unicast IP header and continues to forward the multicast data down toward the receivers.

If unicast static routes are configured across the tunnel, any unicast packet can be transmitted through the tunnel. If you want to dedicate this tunnel to multicast traffic delivery, you can configure only a static multicast route across the tunnel, so that only multicast packets are transmitted through this tunnel.

NOTE:

To make sure that the maximum transmission unit (MTU) feature operates properly in multicast forwarding through GRE tunnels, configure the same MTU value for all Tunnel interfaces on an HPE 5820X switch or HPE 5800 switch. For more information about MTU configuration on a Tunnel

interface, see Layer 3—IP Services Configuration Guide.

Multicast traceroute

You can use the multicast traceroute utility to trace the path that a multicast traffic flows down from the first-hop router to the last-hop router.

Concepts in multicast traceroute

• Last-hop router—If one of the interfaces of a router connects to the subnet that contains the

given destination address, and if the router can forward multicast streams from the given multicast source onto that subnet, that router is called the "last-hop router." The given

destination address and the given multicast source are specified in the mtracert command.

• First-hop router—The router that directly connects to the multicast source is called the

"first-hop router."

• Querier—The router that sends multicast traceroute requests is called the "querier."

Introduction to multicast traceroute packets

A multicast traceroute packet is a special IGMP packet that is different from common IGMP packets. The difference lies in that its IGMP Type field is set to 0x1F or 0x1E and its destination IP address is a unicast address. The following types of multicast traceroute packets are available:

• Query—Its IGMP Type field set to 0x1F.

• Request—Its IGMP Type field set to 0x1F.

• Response—Its IGMP Type field set to 0x1E.

Process of multicast traceroute

1. The querier sends a query to the last-hop router.

2. After receiving the query, the last-hop router turns the query packet into a request packet by

adding a response data block to the end of the packet. The response data block contains its interface addresses and packet statistics. The last-hop router then forwards the request packet through unicast to the previous hop for the given multicast source and group.

3. From the last-hop router to the multicast source, each hop adds a response data block to the

end of the request packet and unicasts it to the previous hop.

4. When the first-hop router receives the request packet, it changes the packet type to indicate a

response packet. Then, it sends the completed packet through unicast to the querier.

Configuration task list

Task Remarks

Enabling IP multicast routing Required.

Configuring static multicast routes Optional.

Configuring a multicast routing policy Optional.

Configuring multicast routing and forwarding

Configuring a multicast forwarding range Optional.

Configuring the multicast forwarding table size Optional.

Tracing a multicast path Optional.

Enabling multicast optimization Optional.

NOTE:

• The switch periodically sends a PIM hello message to PIM routers on the subnets represented by its primary address to establish and maintain PIM neighbor relationships. The hello message carries a list of secondary IP addresses, which is obtained and maintained by other PIM neighbors as next hops of multicast routes. In this way, multicast packets can be forwarded to the subnets represented by secondary IP addresses.

• For more information about primary and secondary IP addresses, see Layer 3—IP Services Configuration Guide.

Enabling IP multicast routing

Before you configure any Layer 3 multicast functionality, enable IP multicast routing first.

Enabling IP multicast routing for the public network

Step Command Remarks

1. Enter system view.

system-view

N/A

2. Enable IP multicast routing.

multicast routing-enable

Disabled by default.

Enabling IP multicast routing in a VPN instance

Step Command Remarks

1. Enter system view.

2. Create a VPN instance and

enter VPN instance view.

3. Configure a route

distinguisher (RD) for the VPN instance.

4. Enable IP multicast routing.

system-view ip vpn-instance

vpn-instance-name

route-distinguisher

multicast routing-enable

N/A

No RD is configured by default.

Disabled by default.

For more information about the ip vpn-instance and route-distinguisher commands, see MPLS Command Reference.

Configuring multicast routing and forwarding

This section describes how to configure multicast routing and forwarding.

Configuration prerequisites

Before you configure multicast routing and forwarding, complete the following tasks:

• Configure a unicast routing protocol so that all devices in the domain are interoperable at the

network layer.

• Enable PIM (PIM-DM or PIM-SM).

• Determine the maximum number of downstream nodes for a single multicast forwarding table

entry.

• Determine the maximum number of entries in the multicast forwarding table.

Configuring static multicast routes

By configuring a static multicast route for a given multicast source, you can specify an RPF interface or an RPF neighbor for multicast traffic from that source. If you want to remove a specific static

multicast route, use the undo ip rpf-route-static command. If you want to remove all static multicast routes, use the delete ip rpf-route-static command.

When you configure a static multicast route, you cannot specify an RPF neighbor by providing the

type and number (interface-type interface-number) of the interface if the interface of the RPF

neighbor is a Layer 3 Ethernet port, Layer 3 aggregate interface, Loopback interface, or VLAN

interface. Instead, you can specify such an RPF neighbor only by its address (rpf-nbr-address).

To configure a static multicast route:

Step Command Remarks

1. Enter system

view.

2. Configure a

static multicast route.

3. Delete static

multicast routes.

system-view

ip rpf-route-static [ vpn-instance

vpn-instance-name ] source-address { mask | mask-length } [ protocol [ process-id ] ] [ policy-name ] { rpf-nbr-address | interface-type interface-number } [ order-number ]

delete ip rpf-route-static [ vpn-instance

vpn-instance-name ]

preference

route-policy

preference ] [

order

N/A

No static multicast route configured by default.

Optional.

Configuring a multicast routing policy

You can configure the router to determine the RPF route based on the longest match principle. For more information about RPF route selection, see "RPF check process."

By configuring per-source or per-source-and-group load splitting, you can optimize the traffic delivery when multiple data flows are handled.

Configuring a multicast routing policy for the public network

Step Command Remarks

1. Enter system view.

2. Configure the device to

select the RPF route based on the longest match.

3. Configure multicast load

splitting.

system-view

multicast longest-match

multicast load-splitting

source-group

Configuring a multicast routing policy in a VPN instance

source

{

}

N/A

The route with the highest priority is selected as the RPF route by default.

Optional.

Disabled by default.

This command does not take effect in BIDIR-PIM.

Step Command Remarks

1. Enter system view.

2. Enter VPN instance view.

system-view ip vpn-instance

vpn-instance-name

N/A

Step Command Remarks

3. Configure the device to

select the RPF route based on the longest match.

4. Configure multicast load

splitting.

multicast longest-match

multicast load-splitting

source

{

source-group

}

Configuring a multicast forwarding range

Multicast packets do not travel without a boundary in a network. The multicast data corresponding to each multicast group must be transmitted within a definite scope. You can configure a forwarding boundary specific to a particular multicast group on all interfaces that support multicast forwarding. A multicast forwarding boundary sets the boundary condition for the multicast groups in the specified range. If the destination address of a multicast packet matches the set boundary condition, the packet is not forwarded. After you configure an interface as a multicast boundary, the interface can no longer forward multicast packets (including packets sent from the local device), or receive multicast packets.

To configure a multicast forwarding range:

The route with the highest priority is selected as the RPF route by default.

Optional.

Disabled by default.

This command does not take effect in BIDIR-PIM.

Step Command Remarks

1. Enter system view.

2. Enter interface view.

3. Configure a multicast

forwarding boundary.

system-view interface

interface-number

multicast boundary

group-address { mask | mask-length }

interface-type

N/A

No forwarding boundary by default.

Configuring the multicast forwarding table size

The router maintains the corresponding forwarding entry for each multicast packet that it receives. Excessive multicast routing entries, however, can exhaust the router's memory and cause lower performance. You can set an upper limit on the number of entries in the multicast forwarding table based on the networking situation and the performance requirements. If the configured upper limit is smaller than the number of existing entries in the multicast forwarding table, the entries in excess are not deleted immediately. The multicast routing protocol that runs on the router will delete them. The router will no longer add new multicast forwarding entries until the number of existing multicast forwarding entries decreases below the upper limit.

When the router forwards multicast data, it replicates a copy of the multicast data for each downstream node and forwards the data. Each of these downstream nodes is a branch of the multicast distribution tree. You can configure the maximum number of downstream nodes (the maximum number of outgoing interfaces) for a single entry in the multicast forwarding table to lessen the burden on the router. If the configured upper limit is smaller than the number of existing downstream nodes for a forwarding entry, the downstream nodes in excess are not deleted immediately. The multicast routing protocol that runs on the router will delete them. The router will no longer update the newly added downstream nodes for the forwarding entry until the number of existing downstream nodes for the forwarding entry decreases below the upper limit.

Configuring the multicast forwarding table size for the public network

Step Command Remarks

1. Enter system view.

system-view

N/A

2. Configure the maximum

number of entries in the multicast forwarding table.

3. Configure the maximum

number of downstream nodes for a single multicast forwarding entry.

multicast forwarding-table route-limit

multicast forwarding-table downstream-limit

limit

Configuring the multicast forwarding table size in a VPN instance

Step Command Remarks

1. Enter system view.

2. Enter VPN instance view.

3. Configure the maximum

number of entries in the multicast forwarding table.

4. Configure the maximum

number of downstream nodes for a single route in the multicast forwarding table.

system-view ip vpn-instance

vpn-instance-name

multicast forwarding-table route-limit

multicast forwarding-table downstream-limit

limit

Optional.

By default, the upper limit is 4000 for the HPE 5800 switches, and 2000 for the HPE 5820X switches.

Optional.

By default, the upper limit is 128.

N/A

Optional.

By default, the upper limit is 4000 for the HPE 5800 switches, and 2000 for the HPE 5820X switches.

Optional.

By default, the upper limit is 128.

Tracing a multicast path

You can use the mtracert command to trace the path down which the multicast traffic flows from a

given first-hop router to the last-hop router.

To trace a multicast path:

Task Command Remarks

Trace a multicast path.

mtracert

[ [ last-hop-router-address ] group-address ]

source-address

Enabling multicast optimization

The establishment of multicast forwarding entries uses hash algorithm, which inevitably leads to hash collisions. When hash collisions occur, multicast packets are lost because proper multicast forwarding entries for them cannot be established.

To reduce the probability of hash collisions, you can enable the multicast optimization feature.

To enable multicast optimization:

Step Command Remarks

1. Enter system view.

system-view

Available in any view.

N/A

Step Command Remarks

2. Enable multicast

optimization.

NOTE:

multicast-optimization enable

By default, the multicast optimization feature is disabled.

Enabling the multicast optimization feature reduces the efficiency of establishing multicast forwarding entries.

Displaying and maintaining multicast routing and forwarding

CAUTION:

The reset commands might cause multicast data transmission failures.

To display and maintain multicast routing and forwarding:

Task Command Remarks

Display multicast boundary information.

Display multicast forwarding table information.

Display the DF information of the multicast forwarding table.

Display information about the multicast routing table.

display multicast [ all-instance

vpn-instance-name ] [ mask | mask-length ] ] [

interface-number ] [ regular-expression ]

display multicast [ all-instance

vpn-instance-name ] [ source-address [ group-address [

incoming-interface

interface-number |

exclude | include | match

{

interface-number | slot-number ] * [

include display multicast [ all-instance

vpn-instance-name ] [ rp-address ] [

exclude display multicast [ all-instance

vpn-instance-name ] [ source-address [ group-address [

incoming-interface

interface-number |

{

interface-number |

} regular-expression ]

include

exclude | include | match

include

} regular-expression ]

boundary

begin

{

forwarding-table

mask

{ mask | mask-length } ] |

{ interface-type

port-info

forwarding-table df-info

slot

slot-number ] [

} regular-expression ]

routing-table

mask

{ mask | mask-length } ] |

{ interface-type

vpn-instance

[ group-address

interface

{ mask | mask-length } ] |

} |

] [ | {

{ mask | mask-length } ] |

} |

} ] * [ | {

interface-type

exclude

outgoing-interface

} { interface-type

statistics

begin

outgoing-interface

} { interface-type

include

vpn-instance

slot

exclude

vpn-instance

begin

{

vpn-instance

begin

exclude

Available in any view.

}

Available in any view.

Display information about the static multicast routing table.

Display RPF route information about the

display multicast routing-table vpn-instance

[ source-address { mask-length | mask } ] [

exclude

display multicast [ all-instance | vpn-instance

vpn-instance-name ]

include

} regular-expression ]

rpf-info

all-instance

[

static

{

source-address

begin

Available in any view.

Task Command Remarks

specified multicast source.

[ group-address ] [ regular-expression ]

{

begin

exclude

include

}

Available in user view.

When a multicast forwarding entry is removed, the associated multicast routing entry is also removed.

Available in user view.

When a multicast routing entry is removed, the associated multicast forwarding entry is removed.

Clear forwarding entries from the multicast forwarding table.

Clear routing entries from the multicast routing table.

reset multicast [ all-instance | vpn-instance

vpn-instance-name ] { { source-address [ group-address [

incoming-interface

interface-number |

reset multicast [ all-instance | vpn-instance

vpn-instance-name ] { { source-address [ group-address [

incoming-interface

interface-number |

forwarding-table

mask

{ mask | mask-length } ] |

mask

{ mask | mask-length } ] |

{ interface-type

routing-table

mask

{ mask | mask-length } ] |

{ interface-type

all

} } * |

{ mask | mask-length } ] |

all

} } * |

}

For more information about designated forwarder (DF), see "Configuring PIM."

Multicast routing and forwarding configuration examples

This section describes details about multicast routing and forwarding configuration examples.

RPF route change configuration example

Network requirements

As shown in Figure 30:

• PIM-DM runs in the network.

• All switches in the network support multicast.

• Switch A, Switch B and Switch C run OSPF.

• Typically, the receiver can receive the multicast data from the source through the path: Switch A

to Switch B, which is the same as the unicast route.

Configure the switches so that the receiver can receive the multicast data from the source through the path: Switch A to Switch C to Switch B. This path is different from the unicast route.

Figure 30 Network diagram

Configuration procedure

1. Assign an IP address and subnet mask to each interface according to Figure 30. (Details not

shown.)

2. Configure OSPF on the switches in the PIM-DM domain to meet the following requirements:

(Details not shown.)

{ The switches are interoperable at the network layer.

{ The switches can dynamically update their routing information.

3. Enable IP multicast routing globally, IGMP and PIM-DM:

# On Switch B, enable IP multicast routing, enable IGMP on VLAN-interface 100, and enable PIM-DM on each interface.

<SwitchB> system-view [SwitchB] multicast routing-enable [SwitchB] interface vlan-interface 100 [SwitchB-Vlan-interface100] igmp enable [SwitchB-Vlan-interface100] pim dm [SwitchB-Vlan-interface100] quit [SwitchB] interface vlan-interface 101 [SwitchB-Vlan-interface101] pim dm [SwitchB-Vlan-interface101] quit [SwitchB] interface vlan-interface 102 [SwitchB-Vlan-interface102] pim dm [SwitchB-Vlan-interface102] quit

# On Switch A, enable IP multicast routing, and enable PIM-DM on each interface.

<SwitchA> system-view [SwitchA] multicast routing-enable [SwitchA] interface vlan-interface 200 [SwitchA-Vlan-interface200] pim dm [SwitchA-Vlan-interface200] quit

[SwitchA] interface vlan-interface 102 [SwitchA-Vlan-interface102] pim dm [SwitchA-Vlan-interface102] quit [SwitchA] interface vlan-interface 103 [SwitchA-Vlan-interface103] pim dm [SwitchA-Vlan-interface103] quit

# Enable IP multicast routing and PIM-DM on Switch C in the same way Switch A is configured. (Details not shown.)

4. Display the RPF route to Source on Switch B.

The output shows that the current RPF route on Switch B is contributed by a unicast routing protocol and the RPF neighbor is Switch A.

5. Configure a static multicast route on Switch B, and specify Switch C as its RPF neighbor on the

route to Source.

[SwitchB] ip rpf-route-static 50.1.1.100 24 20.1.1.2

Verifying the configuration

# Display information about the RPF route to the source on Switch B.

[SwitchB] display multicast rpf-info 50.1.1.100 RPF information about source 50.1.1.100: RPF interface: Vlan-interface101, RPF neighbor: 20.1.1.2 Referenced route/mask: 50.1.1.0/24 Referenced route type: multicast static Route selection rule: preference-preferred Load splitting rule: disable

The output shows that the RPF route on Switch B has changed. It is now the configured static multicast route, and the RPF neighbor is now Switch C.

RPF route creation configuration example

Network requirements

As shown in Figure 31:

• PIM-DM runs in the network.

• All switches in the network support IP multicast.

• Switch B and Switch C run OSPF, but have no unicast routes to Switch A.

• Typically, the receiver can receive the multicast data from the source 1 in the OSPF domain.

Configure the switches so that the receiver can receive multicast data from the source 2, which is outside the OSPF domain.

Figure 31 Network diagram

Switch A Switch B Switch C

Vlan-int102

30.1.1.2/24

Vlan-int300

50.1.1.1/24

50.1.1.100/24

Multicast static route

Configuration procedure

1. Assign an IP address and subnet mask to each interface according to Figure 31. (Details not

shown.)

2. Configure OSPF on Switch B and Switch C to meet the following requirements: (Details not

shown.)

{ The switches are interoperable at the network layer.

{ The switches can dynamically update their routing information.

3. Enable IP multicast routing globally, IGMP and PIM-DM:

# On Switch C, enable IP multicast routing, enable IGMP on VLAN-interface 100, and enable PIM-DM on each interface.

<SwitchC> system-view [SwitchC] multicast routing-enable [SwitchC] interface vlan-interface 100 [SwitchC-Vlan-interface100] igmp enable [SwitchC-Vlan-interface100] pim dm [SwitchC-Vlan-interface100] quit [SwitchC] interface vlan-interface 101 [SwitchC-Vlan-interface101] pim dm [SwitchC-Vlan-interface101] quit

# On Switch A, enable IP multicast routing, and enable PIM-DM on each interface.

<SwitchA> system-view [SwitchA] multicast routing-enable [SwitchA] interface vlan-interface 300 [SwitchA-Vlan-interface300] pim dm [SwitchA-Vlan-interface300] quit [SwitchA] interface vlan-interface 102 [SwitchA-Vlan-interface102] pim dm [SwitchA-Vlan-interface102] quit

# Enable IP multicast routing and PIM-DM on Switch B in the same way Switch A is configured. (Details not shown.)

4. Display the RPF routes to Source 2 on Switch B and Switch C.

PIM-DM

Vlan-int102

30.1.1.1/24

Vlan-int200

40.1.1.1/24

OSPF domain

Vlan-int101

20.1.1.1/24

Vlan-int101

20.1.1.2/24

Source 1Source 2 Receiver

40.1.1.100/24 10.1.1.100/24

Vlan-int100

10.1.1.1/24

[SwitchB] display multicast rpf-info 50.1.1.100 [SwitchC] display multicast rpf-info 50.1.1.100

No information is displayed, because no RPF route to the source 2 exists on Switch B or Switch C.

5. Configure a static multicast route:

# Configure a static multicast route on Switch B, and specify Switch A as its RPF neighbor on the route to Source 2.

[SwitchB] ip rpf-route-static 50.1.1.100 24 30.1.1.2

# Configure a static multicast route on Switch C, and specify Switch B as its RPF neighbor on the route to Source 2.

[SwitchC] ip rpf-route-static 10.1.1.100 24 20.1.1.2

Verifying the configuration

# Display the RPF routes to the source 2 on Switch B and Switch C.

[SwitchB] display multicast rpf-info 50.1.1.100 RPF information about source 50.1.1.100: RPF interface: Vlan-interface102, RPF neighbor: 30.1.1.2 Referenced route/mask: 50.1.1.0/24 Referenced route type: multicast static Route selection rule: preference-preferred Load splitting rule: disable [SwitchC] display multicast rpf-info 50.1.1.100 RPF information about source 50.1.1.100: RPF interface: Vlan-interface101, RPF neighbor: 20.1.1.2 Referenced route/mask: 50.1.1.0/24 Referenced route type: multicast static Route selection rule: preference-preferred Load splitting rule: disable

The output shows that the RPF routes to Source 2 exist on Switch B and Switch C. The routes are the configured static routes.

Multicast forwarding over a GRE tunnel

Network requirements

As shown in Figure 32:

• Multicast routing and PIM-DM are enabled on Switch A and Switch C.

• Switch B does not support multicast.

• OSPF is running on Switch A, Switch B, and Switch C.

Configure the switches so that the receiver can receive the multicast data from Source.

Figure 32 Network diagram

Configuration procedure

1. Assign an IP address and subnet mask to each interface according to Figure 32. (Details not

shown.)

2. Configure a GRE tunnel:

# Create service loopback group 1 on Switch A, and specify its service type as Tunnel.

<SwitchA> system-view [SwitchA] service-loopback group 1 type tunnel

# Disable STP, LLDP and NDP on interface GigabitEthernet 1/0/3 of Switch A, and add the interface to service loopback group 1. GigabitEthernet 1/0/3 does not belong to VLAN 100 or VLAN 101.

[SwitchA] interface gigabitethernet 1/0/3 [SwitchA-GigabitEthernet1/0/3] undo stp enable [SwitchA-GigabitEthernet1/0/3] undo ndp enable [SwitchA-GigabitEthernet1/0/3] undo lldp enable [SwitchA-GigabitEthernet1/0/3] port service-loopback group 1 [SwitchA-GigabitEthernet1/0/3] quit

# Create interface Tunnel 0 on Switch A, configure the IP address and subnet mask for the interface, and

[SwitchA] interface tunnel 0 [SwitchA-Tunnel0] ip address 50.1.1.1 24 [SwitchA-Tunnel0] service-loopback-group 1

# Specify the tunnel encapsulation mode as GRE over IPv4 for interface Tunnel 0 on Switch A and specify the source and destination addresses for the interface.

[SwitchA-Tunnel0] tunnel-protocol gre [SwitchA-Tunnel0] source 20.1.1.1 [SwitchA-Tunnel0] destination 30.1.1.2 [SwitchA-Tunnel0] quit

# Create service loopback group 1 on Switch C and specify its service type as Tunnel.

<SwitchC> system-view [SwitchC] service-loopback group 1 type tunnel

# Disable STP, LLDP and NDP on interface GigabitEthernet 1/0/3 of Switch C, and add the interface to service loopback group 1. GigabitEthernet 1/0/3 does not belong to VLAN 200 or VLAN 102.

[SwitchC] interface gigabitethernet 1/0/3 [SwitchC-GigabitEthernet1/0/3] undo stp enable

reference service loopback group 1 on interface Tunnel 0.

HP FlexFabric 5800, FlexFabric 5820X IP Multicast Configuration Guide

Specifications and Main Features

Frequently Asked Questions

User Manual

Multicast overview

Information transmission techniques

Unicast

Broadcast

Multicast

Multicast features

Common notations in multicast

Multicast advantages and applications

Multicast advantages

Multicast applications

Multicast models

ASM model

SFM model

SSM model

Multicast architecture

Multicast addresses

IP multicast addresses

Ethernet multicast MAC addresses

Multicast protocols

Layer 3 multicast protocols

Layer 2 multicast protocols

Multicast packet forwarding mechanism

Multicast support for VPNs

Introduction to VPN instances

Multicast application in VPNs

Configuring IGMP snooping

Overview

IGMP snooping basic concepts

IGMP snooping related ports

Aging timers for dynamic ports in IGMP snooping and related messages and actions

How IGMP snooping operates

When receiving a general query

When receiving a membership report

When receiving a leave message

IGMP snooping proxying

Protocols and standards

IGMP snooping configuration task list

Configuring basic IGMP snooping functions

Configuration prerequisites

Enabling IGMP snooping

Configuration guidelines

Configuration procedure

Specifying the version of IGMP snooping

Setting the maximum number of IGMP snooping forwarding entries

Configuring static multicast MAC address entries

Configuration guidelines

Configuration procedure

Configuring IGMP snooping port functions

Configuration prerequisites

Setting aging timers for dynamic ports

Setting aging timers for dynamic ports globally

Setting aging timers for the dynamic ports in a VLAN

Configuring static ports

Configuration guidelines

Configuration procedure

Configuring a port as a simulated member host

Enabling IGMP snooping fast-leave processing

Enabling IGMP snooping fast-leave processing globally

Enabling IGMP snooping fast-leave processing on a port

Disabling a port from becoming a dynamic router port

Configuring an IGMP snooping querier

Configuration prerequisites

Enabling IGMP snooping querier

Configuring parameters for IGMP queries and responses

Configuring the global parameters for IGMP queries and responses

Configuring the parameters for IGMP queries and responses in a VLAN

Configuring the source IP addresses for IGMP queries

Configuring IGMP snooping proxying

Configuration prerequisites

Enabling IGMP snooping proxying

Configuring the source IP addresses for the IGMP messages sent by the proxy

Configuring IGMP snooping policies

Configuration prerequisites

Configuring a multicast group filter

Configuration guidelines

Configuration procedure