HPP Enterprises FlexNetwork 7500 Configuration Manual

Download

HPE FlexNetwork 7500 Switch Series

IP Multicast Configuration Guide

P Software Document version: 6W100-20161230

art number: 5200-1936

version: 7500-CMW710-R7524

Enterprise products and services are set forth in the express warranty statements accompanying such products and services. Nothing herein should be construed as constituting an additional warranty. Hewlett Packard Enterprise shall not be liable for technical or editorial errors or omissions contained herein.

Confidential computer software. Valid license from Hewlett Packard Enterprise required for possession, use, or copying. Consistent with FAR 12.211 and 12.212, Commercial Computer Software, Computer Software Documentation, and Technical Data for Commercial Items are licensed to the U.S. Government under vendor’s standard commercial license.

Links to third-party websites take you outside the Hewlett Packard Enterprise website. Hewlett Packard Enterprise has no control over and is not responsible for information outside the Hewlett Packard Enterprise website.

Acknowledgments

Intel®, Itanium®, Pentium®, Intel Inside®, and the Intel Inside logo are trademarks of Intel Corporation in the United States and other countries.

Microsoft® and Windows® are trademarks of the Microsoft group of companies. Adobe® and Acrobat® are trademarks of Adobe Systems Incorporated. Java and Oracle are registered trademarks of Oracle and/or its affiliates. UNIX® is a registered trademark of The Open Group.

Contents

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

Introduction to multicast ····································································································································· 1

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

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

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

Multicast protocols ····································································································································· 8 Multicast packet forwarding mechanism ·········································································································· 10 Multicast support for VPNs······························································································································· 11

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

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

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

IGMP snooping ports ······························································································································· 13

How IGMP snooping works ······················································································································ 15

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

Protocols and standards ·························································································································· 17

Configuration restrictions and guidelines ································································································· 17 IGMP snooping configuration task list ·············································································································· 17

IGMP snooping configuration task list for VLANs ···················································································· 18

IGMP configuration task list for VSIs········································································································ 18 Configuring basic IGMP snooping features ····································································································· 19

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

Specifying an IGMP snooping version ····································································································· 20

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

Configuring static multicast MAC address entries ···················································································· 21

Setting the IGMP last member query interval ·························································································· 21 Configuring IGMP snooping port features ········································································································ 22

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

Configuring static ports ···························································································································· 23

Configuring a port as a simulated member host ······················································································ 24

Enabling fast-leave processing ················································································································ 24

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

Configuration prerequisites ······················································································································ 26

Enabling the IGMP snooping querier ······································································································· 26

Configuring parameters for IGMP general queries and responses ·························································· 26 Enabling IGMP snooping proxying ··················································································································· 27 Configuring parameters for IGMP messages ··································································································· 27

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

Configuring the source IP address for IGMP messages ·········································································· 28

Setting the 802.1p priority for IGMP messages ······················································································· 29 Configuring IGMP snooping policies ················································································································ 30

Configuring a multicast group policy ········································································································ 30

Enabling multicast source port filtering ···································································································· 31

Enabling dropping unknown multicast data ······························································································ 31

Enabling IGMP report suppression ·········································································································· 32

Setting the maximum number of multicast groups on a port ···································································· 32

Enabling multicast group replacement ····································································································· 33

Enabling host tracking ······························································································································ 34 Displaying and maintaining IGMP snooping ···································································································· 34 IGMP snooping configuration examples ·········································································································· 36

Group policy and simulated joining configuration example (for VLANs) ·················································· 36

Static port configuration example (for VLANs) ························································································· 38

IGMP snooping querier configuration example (for VLANs) ···································································· 40

IGMP snooping proxying configuration example (for VLANs) ·································································· 43

IGMP snooping configuration example (for VXLANs) ·············································································· 44 Troubleshooting IGMP snooping ····················································································································· 49

Layer 2 multicast forwarding cannot function ··························································································· 49

Multicast group policy does not work ······································································································· 50

Configuring PIM snooping ············································································ 51

Overview ·························································································································································· 51 Configuring PIM snooping ································································································································ 52 Displaying and maintaining PIM snooping ······································································································· 53 PIM snooping configuration example ··············································································································· 53

Network requirements ······························································································································ 53

Configuration procedure ··························································································································· 54

Verifying the configuration ························································································································ 55 Troubleshooting PIM snooping ························································································································ 57

PIM snooping does not work on a Layer 2 device ··················································································· 57

Configuring multicast VLANs ······································································· 58

Overview ·························································································································································· 58 Multicast VLAN configuration task list ·············································································································· 60 Configuring a sub-VLAN-based multicast VLAN ······························································································ 60

Configuration prerequisites ······················································································································ 60

Configuration restrictions and guidelines ································································································· 60

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

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

Configuring user port attributes ················································································································ 61

Assigning user ports to a multicast VLAN ································································································ 62 Setting the maximum number of multicast VLAN forwarding entries ······························································· 62 Displaying and maintaining multicast VLANs ··································································································· 63 Multicast VLAN configuration examples ·········································································································· 63

Sub-VLAN-based multicast VLAN configuration example ······································································· 63

Port-based multicast VLAN configuration example ·················································································· 66

Configuring multicast routing and forwarding ··············································· 70

RPF check mechanism ···························································································································· 70

Static multicast routes ······························································································································ 72

Multicast forwarding across unicast subnets ···························································································· 73 Configuration task list ······································································································································· 74 Enabling IP multicast routing···························································································································· 74 Configuring multicast routing and forwarding ··································································································· 75

Configuring static multicast routes ··········································································································· 75

Specifying the longest prefix match principle ··························································································· 75

Configuring multicast load splitting··········································································································· 76

Configuring a multicast forwarding boundary ··························································································· 76 Enabling multicast forwarding between sub-VLANs of a super VLAN ····························································· 76 Displaying and maintaining multicast routing and forwarding ·········································································· 77 Configuration examples ··································································································································· 79

Changing an RPF route ··························································································································· 79

Creating an RPF route ····························································································································· 81

Multicast forwarding over a GRE tunnel ··································································································· 82 Troubleshooting multicast routing and forwarding ··························································································· 85

Static multicast route failure ····················································································································· 85

Configuring IGMP ························································································ 86

IGMPv1 overview ····································································································································· 86

IGMPv2 enhancements ···························································································································· 87

IGMPv3 enhancements ···························································································································· 88

IGMP SSM mapping ································································································································ 89

IGMP proxying ········································································································································· 90

IGMP support for VPNs ···························································································································· 91

Protocols and standards ·························································································································· 91 IGMP configuration task list ····························································································································· 92 Configuring basic IGMP features ····················································································································· 92

Enabling IGMP ········································································································································· 92

Specifying an IGMP version ····················································································································· 93

Configuring a static group member ·········································································································· 93

Configuring a multicast group policy ········································································································ 93 Adjusting IGMP performance ··························································································································· 94

Configuring IGMP query and response parameters ················································································· 94

Enabling fast-leave processing ················································································································ 96 Configuring IGMP SSM mappings ··················································································································· 97

Configuration prerequisites ······················································································································ 97

Configuration procedure ··························································································································· 97 Configuring IGMP proxying ······························································································································ 97

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

Enabling multicast forwarding on a non-querier interface ········································································ 98

Configuring multicast load splitting on an IGMP proxy············································································· 98 Enabling IGMP NSR ········································································································································ 99 Displaying and maintaining IGMP ···················································································································· 99 IGMP configuration examples ························································································································ 100

Basic IGMP features configuration examples ························································································ 100

IGMP SSM mapping configuration example ·························································································· 102

IGMP proxying configuration example ··································································································· 105 Troubleshooting IGMP ··································································································································· 106

No membership information on the receiver-side router ········································································ 106

Inconsistent membership information on the routers on the same subnet············································· 106

Configuring PIM ························································································· 108

PIM-DM overview ··································································································································· 108

PIM-SM overview ··································································································································· 110

BIDIR-PIM overview ······························································································································· 116

Administrative scoping overview ············································································································ 119

PIM-SSM overview ································································································································· 121

Relationship among PIM protocols ········································································································ 122

PIM support for VPNs ···························································································································· 123

Protocols and standards ························································································································ 123 Configuring PIM-DM······································································································································· 123

PIM-DM configuration task list ··············································································································· 124

Configuration prerequisites ···················································································································· 124

Enabling PIM-DM ··································································································································· 124

Enabling the state refresh feature ·········································································································· 124

Configuring state refresh parameters ····································································································· 125

Configuring PIM-DM graft retry timer ····································································································· 125 Configuring PIM-SM ······································································································································· 126

PIM-SM configuration task list················································································································ 126

Configuration prerequisites ···················································································································· 126

Enabling PIM-SM ··································································································································· 126

Configuring an RP ·································································································································· 127

Configuring a BSR ································································································································· 129

Configuring multicast source registration ······························································································· 131

Configuring the switchover to SPT ········································································································· 132

Configuration restrictions and guidelines ······························································································· 132

BIDIR-PIM configuration task list ··········································································································· 132

Configuration prerequisites ···················································································································· 133

Enabling BIDIR-PIM ······························································································································· 133

Configuring an RP ·································································································································· 133

Configuring a BSR ································································································································· 135

iii

Configuring PIM-SSM ···································································································································· 137

PIM-SSM configuration task list ············································································································· 138

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

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

Configuring the SSM group range ·········································································································· 138 Configuring common PIM features················································································································· 139

Configuration task list ····························································································································· 139

Configuration prerequisites ···················································································································· 139

Configuring a multicast source policy ····································································································· 139

Configuring a PIM hello policy················································································································ 140

Configuring PIM hello message options ································································································· 140

Configuring common PIM timers ············································································································ 142

Setting the maximum size of a join or prune message ·········································································· 143

Enabling BFD for PIM ···························································································································· 143

Enabling PIM passive mode ··················································································································· 143

Enabling PIM NSR ································································································································· 144

Enabling SNMP notifications for PIM ····································································································· 144

Setting a DSCP value for outgoing PIM messages ················································································ 144 Displaying and maintaining PIM ····················································································································· 145 PIM configuration examples ··························································································································· 145

PIM-DM configuration example ·············································································································· 145

PIM-SM non-scoped zone configuration example ················································································· 148

PIM-SM admin-scoped zone configuration example·············································································· 151

BIDIR-PIM configuration example ·········································································································· 156

PIM-SSM configuration example············································································································ 160 Troubleshooting PIM ······································································································································ 163

A multicast distribution tree cannot be correctly built ············································································· 163

Multicast data is abnormally terminated on an intermediate router························································ 164

An RP cannot join an SPT in PIM-SM ···································································································· 164

An RPT cannot be built or multicast source registration fails in PIM-SM ··············································· 164

Configuring MSDP ····················································································· 166

How MSDP works ·································································································································· 166

MSDP support for VPNs ························································································································ 171

Protocols and standards ························································································································ 171 MSDP configuration task list ·························································································································· 172 Configuring basic MSDP features ·················································································································· 172

Configuration prerequisites ···················································································································· 172

Enabling MSDP ······································································································································ 172

Specifying an MSDP peer ······················································································································ 173

Configuring a static RPF peer ················································································································ 173 Configuring an MSDP peering connection ····································································································· 173

Configuration prerequisites ···················································································································· 173

Configuring a description for an MSDP peer ·························································································· 174

Configuring an MSDP mesh group ········································································································ 174

Controlling MSDP peering connections ································································································· 174 Configuring SA message-related parameters ································································································ 175

Configuration prerequisites ···················································································································· 175

Enabling multicast data encapsulation in SA messages ········································································ 175

Configuring the originating RP of SA messages ···················································································· 176

Configuring SA request messages ········································································································· 176

Configuring SA message policies ·········································································································· 177

Configuring the SA cache mechanism ··································································································· 178 Enabling MSDP NSR ····································································································································· 178 Displaying and maintaining MSDP ················································································································· 178 MSDP configuration examples ······················································································································· 179

PIM-SM inter-domain multicast configuration ························································································ 179

Inter-AS multicast configuration by leveraging static RPF peers ··························································· 184

Anycast RP configuration ······················································································································· 188

SA message filtering configuration ········································································································· 192 Troubleshooting MSDP ·································································································································· 195

MSDP peers stay in disabled state ········································································································ 196

No SA entries exist in the router's SA message cache ·········································································· 196

No exchange of locally registered (S, G) entries between RPs ····························································· 196

Configuring multicast VPN ········································································· 197

MD VPN overview ·································································································································· 198

Protocols and standards ························································································································ 201 How MD VPN works······································································································································· 201

Default-MDT establishment ···················································································································· 202

Default-MDT-based delivery ·················································································································· 205

MDT switchover ····································································································································· 208

Inter-AS MD VPN ··································································································································· 209 Configuration restrictions and guidelines ······································································································· 212 Multicast VPN configuration task list ·············································································································· 212 Configuring MD VPN ······································································································································ 213

Configuration prerequisites ···················································································································· 213

Enabling IP multicast routing for a VPN instance ··················································································· 213

Creating an MD for a VPN instance ······································································································· 214

Create an MD address family················································································································· 214

Specifying the default-group ·················································································································· 215

Specifying the MD source interface ······································································································· 215

Configuring MDT switchover parameters ······························································································· 216

Configuring the RPF vector feature ········································································································ 216

Enabling data-group reuse logging ········································································································ 217 Configuring BGP MDT ··································································································································· 217

Configuration prerequisites ···················································································································· 217

Configuring BGP MDT peers or peer groups ························································································· 217

Configuring a BGP MDT route reflector ································································································· 218 Displaying and maintaining multicast VPN····································································································· 219 Multicast VPN configuration examples··········································································································· 219

Intra-AS MD VPN configuration example ······························································································· 219

MD VPN inter-AS option B configuration example ················································································· 233

MD VPN inter-AS option C configuration example ················································································· 247 Troubleshooting MD VPN ······························································································································ 260

A default-MDT cannot be established ···································································································· 260

An MVRF cannot be created ·················································································································· 260

Configuring MLD snooping ········································································ 262

MLD snooping ports ······························································································································· 262

How MLD snooping works ····················································································································· 264

MLD snooping proxying ························································································································· 265

Protocols and standards ························································································································ 266 Configuration restrictions and guidelines ······································································································· 266 MLD snooping configuration task list ············································································································· 267

MLD snooping configuration task list for VLANs ···················································································· 267

MLD snooping configuration task list for VSIs························································································ 267 Configuring basic MLD snooping features ····································································································· 268

Enabling MLD snooping ························································································································· 268

Specifying an MLD snooping version ····································································································· 269

Setting the maximum number of MLD snooping forwarding entries ······················································ 270

Configuring static IPv6 multicast MAC address entries ········································································· 270

Setting the MLD last listener query interval ···························································································· 271 Configuring MLD snooping port features ······································································································· 271

Setting aging timers for dynamic ports ··································································································· 272

Configuring static ports ·························································································································· 272

Configuring a port as a simulated member host ···················································································· 273

Enabling fast-leave processing ·············································································································· 273

Disabling a port from becoming a dynamic router port ·········································································· 274 Configuring the MLD snooping querier ·········································································································· 275

Configuration prerequisites ···················································································································· 275

Enabling the MLD snooping querier ······································································································· 275

Configuring parameters for MLD general queries and responses ························································· 276 Enabling MLD snooping proxying ·················································································································· 276 Configuring parameters for MLD messages ·································································································· 277

Configuration prerequisites ···················································································································· 277

Configuring source IPv6 addresses for MLD messages ········································································ 277

Setting the 802.1p priority for MLD messages ······················································································· 279 Configuring MLD snooping policies················································································································ 279

Configuring an IPv6 multicast group policy ···························································································· 280

Enabling IPv6 multicast source port filtering ·························································································· 280

Enabling dropping unknown IPv6 multicast data ··················································································· 281

Enabling MLD report suppression ·········································································································· 282

Setting the maximum number of IPv6 multicast groups on a port ·························································· 282

Enabling IPv6 multicast group replacement ··························································································· 282

Enabling host tracking ···························································································································· 283 Displaying and maintaining MLD snooping ···································································································· 284 MLD snooping configuration examples ·········································································································· 285

IPv6 group policy and simulated joining configuration example (for VLANs) ········································· 285

Static port configuration example (for VLANs) ······················································································· 287

MLD snooping querier configuration example (for VLANs) ···································································· 290

MLD snooping proxying configuration example (for VLANs) ································································· 293

MLD snooping configuration example (for VXLANs)·············································································· 294 Troubleshooting MLD snooping ····················································································································· 299

Layer 2 multicast forwarding cannot function ························································································· 299

IPv6 multicast group policy does not work ····························································································· 300

Configuring IPv6 PIM snooping ································································· 301

Overview ························································································································································ 301 Configuring IPv6 PIM snooping······················································································································ 302 Displaying and maintaining IPv6 PIM snooping ····························································································· 303 IPv6 PIM snooping configuration example (for VLANs) ················································································· 303

Network requirements ···························································································································· 303

Configuration procedure ························································································································· 304

Verifying the configuration ······················································································································ 306 Troubleshooting IPv6 PIM snooping ·············································································································· 307

IPv6 PIM snooping does not work on a Layer 2 device ········································································· 307

Configuring IPv6 multicast VLANs ····························································· 308

Overview ························································································································································ 308 IPv6 multicast VLAN configuration task list ···································································································· 310 Configuring a sub-VLAN-based IPv6 multicast VLAN ··················································································· 310

Configuration prerequisites ···················································································································· 310

Configuration guidelines ························································································································· 310

Configuration procedure ························································································································· 311 Configuring a port-based IPv6 multicast VLAN ······························································································ 311

Configuration prerequisites ···················································································································· 311

Configuring user port attributes ·············································································································· 311

Assigning user ports to an IPv6 multicast VLAN ···················································································· 312 Setting the maximum number of IPv6 multicast VLAN forwarding entries ····················································· 312 Displaying and maintaining IPv6 multicast VLANs························································································· 313 IPv6 multicast VLAN configuration examples ································································································ 313

Sub-VLAN-based IPv6 multicast VLAN configuration example ····························································· 313

Port-based IPv6 multicast VLAN configuration example········································································ 316

Configuring IPv6 multicast routing and forwarding ····································· 320

RPF check mechanism ·························································································································· 320

IPv6 multicast forwarding across IPv6 unicast subnets ········································································· 322 Configuration task list ····································································································································· 322 Enabling IPv6 multicast routing ······················································································································ 322 Configuring IPv6 multicast routing and forwarding························································································· 323

Specifying the longest prefix match principle ························································································· 323

Configuring IPv6 multicast load splitting ································································································ 323

Configuring an IPv6 multicast forwarding boundary··············································································· 323

Enabling IPv6 multicast forwarding between sub-VLANs of a super VLAN ··········································· 324 Displaying and maintaining IPv6 multicast routing and forwarding ································································ 324 IPv6 multicast routing and forwarding configuration example ········································································ 326

Network requirements ···························································································································· 326

Configuration procedure ························································································································· 327

Verifying the configuration ······················································································································ 328

Configuring MLD ························································································ 330

How MLDv1 works ································································································································· 330

MLDv2 enhancements ··························································································································· 332

MLD SSM mapping ································································································································ 333

MLD proxying ········································································································································· 334

MLD support for VPNs ··························································································································· 334

Protocols and standards ························································································································ 334 MLD configuration task list ····························································································································· 335 Configuring basic MLD features ····················································································································· 335

Enabling MLD ········································································································································· 335

Specifying an MLD version ···················································································································· 336

Configuring a static group member ········································································································ 336

Configuring an IPv6 multicast group policy ···························································································· 336 Adjusting MLD performance··························································································································· 337

Configuring MLD query and response parameters ················································································ 337

Enabling fast-leave processing ·············································································································· 339 Configuring MLD SSM mappings ··················································································································· 339

Configuration prerequisites ···················································································································· 340

Configuration procedure ························································································································· 340 Configuring MLD proxying······························································································································ 340

Enabling MLD proxying ·························································································································· 340

Enabling IPv6 multicast forwarding on a non-querier interface ······························································ 341

Configuring IPv6 multicast load splitting on an MLD proxy ···································································· 341 Enabling MLD NSR ········································································································································ 342 Displaying and maintaining MLD···················································································································· 342 MLD configuration examples·························································································································· 342

Basic MLD features configuration examples ·························································································· 342

MLD SSM mapping configuration example ···························································································· 345

MLD proxying configuration example ····································································································· 347 Troubleshooting MLD ····································································································································· 349

No member information exists on the receiver-side router ···································································· 349

Inconsistent membership information on the routers on the same subnet············································· 349

Configuring IPv6 PIM ················································································· 350

IPv6 PIM-DM overview ··························································································································· 350

IPv6 PIM-SM overview ··························································································································· 352

IPv6 BIDIR-PIM overview ······················································································································· 358

IPv6 administrative scoping overview ···································································································· 361

IPv6 PIM-SSM overview ························································································································ 363

Relationship among IPv6 PIM protocols ································································································ 364

IPv6 PIM support for VPNs ···················································································································· 365

Protocols and standards ························································································································ 365 Configuring IPv6 PIM-DM ······························································································································ 365

IPv6 PIM-DM configuration task list ······································································································· 366

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

Enabling IPv6 PIM-DM ··························································································································· 366

Enabling the state refresh feature ·········································································································· 366

Configuring state refresh parameters ····································································································· 367

Configuring IPv6 PIM-DM graft retry timer ····························································································· 367 Configuring IPv6 PIM-SM······························································································································· 368

vii

IPv6 PIM-SM configuration task list ······································································································· 368

Configuration prerequisites ···················································································································· 368

Enabling IPv6 PIM-SM ··························································································································· 368

Configuring an RP ·································································································································· 369

Configuring a BSR ································································································································· 371

Configuring IPv6 multicast source registration ······················································································· 373

Configuring the switchover to SPT ········································································································· 374 Configuring IPv6 BIDIR-PIM ·························································································································· 374

Configuration restrictions and guidelines ······························································································· 374

IPv6 BIDIR-PIM configuration task list ··································································································· 374

Configuration prerequisites ···················································································································· 375

Enabling IPv6 BIDIR-PIM ······················································································································· 375

Configuring an RP ·································································································································· 375

Configuring a BSR ································································································································· 377 Configuring IPv6 PIM-SSM ···························································································································· 379

IPv6 PIM-SSM configuration task list ····································································································· 379

Configuration prerequisites ···················································································································· 380

Enabling IPv6 PIM-SM ··························································································································· 380

Configuring the IPv6 SSM group range ································································································· 380 Configuring common IPv6 PIM features ········································································································ 381

Configuration task list ····························································································································· 381

Configuration prerequisites ···················································································································· 381

Configuring an IPv6 multicast source policy ·························································································· 381

Configuring an IPv6 PIM hello policy ····································································································· 382

Configuring IPv6 PIM hello message options ························································································ 382

Configuring common IPv6 PIM timers ···································································································· 383

Setting the maximum size of a join or prune message ·········································································· 385

Enabling BFD for IPv6 PIM ···················································································································· 385

Enabling IPv6 PIM passive mode ·········································································································· 385

Enabling IPv6 PIM NSR ························································································································· 386

Enabling SNMP notifications for IPv6 PIM ····························································································· 386 Displaying and maintaining IPv6 PIM············································································································· 387 IPv6 PIM configuration examples··················································································································· 387

IPv6 PIM-DM configuration example ······································································································ 387

IPv6 PIM-SM non-scoped zone configuration example ········································································· 390

IPv6 PIM-SM admin-scoped zone configuration example ····································································· 393

IPv6 BIDIR-PIM configuration example ·································································································· 399

IPv6 PIM-SSM configuration example ··································································································· 403 Troubleshooting IPv6 PIM ······························································································································ 406

A multicast distribution tree cannot be correctly built ············································································· 406

IPv6 multicast data is abnormally terminated on an intermediate router ··············································· 406

An RP cannot join an SPT in IPv6 PIM-SM ··························································································· 407

An RPT cannot be built or IPv6 multicast source registration fails in IPv6 PIM-SM ······························· 407

Document conventions and icons ······························································ 408

Conventions ··················································································································································· 408 Network topology icons ·································································································································· 409

Support and other resources ····································································· 410

Accessing Hewlett Packard Enterprise Support····························································································· 410 Accessing updates ········································································································································· 410

Websites ················································································································································ 411

Customer self repair ······························································································································· 411

Remote support ······································································································································ 411

Documentation feedback ······················································································································· 411

Index ·········································································································· 413

viii

Multicast overview

Source

Receiver

Host A

Host B

Host C

Host D

Host E

Packets for Host B Packets for Host D Packets for Host E

IP network

Introduction to multicast

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.

By 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.

Information transmission techniques

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

Unicast

In unicast transmis sion, the information sourc e must send a se parate copy of inform ation to each host that needs the inf ormation.

Figure 1 Unicast transmission

In Figure 1, 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. I f a large number of hosts need t he information, the inf ormation source must send a separate copy of the same inform ation 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

Source

Receiver

Host A

Host B

Host C

Host D

Host E

Packets for all hosts

A network segment

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, 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.

Multicast provides point-to-m ultipoint data transmissions with the minimum networ k consumption. When some hosts on the n etwork need multicast inf ormation, the inform ation 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

•

Source

Receiver

Host A

Host B

Host C

Host D

Host E

Packets for the multicast group

IP network

The multicast source s ends only one copy of the inf ormation to a m ulticast group. Host B, Hos t D, and Host E, which are information receivers, 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 data 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

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

Multicast features

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

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

A multicast source is an information sender. It 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.

The group memberships are dynamic. Hosts can join or leave multicast groups at any time.

Multicast groups are not subject to geographic restrictions.

Multicast routers or Layer 3 multicast devices are routers or Layer 3 switches that support Layer

3 multicast. They provide multicast routing and manage multicast group memberships on stub subnets with attached grou p members. A multicast router itself can be a multicast group member.

For a better understandi ng of the m ulticas t c onc ep t, you can compare multic ast tr ans mission to the transmission of TV programs.

Table 1 Comparing TV program transmission and multicast transmissio n

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

channel.

A multicast source sends multicast data to a multicast group.

The receiver starts to receive the multicast data sent by the source to the multicast group.

The receiver leaves the multicast group or joins another group.

Common notations in m ulticast

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

For more inf ormation about the c oncepts RPT and SPT, see "Configuring PIM" and "Configuring IPv6 PIM."

Multicast benefits and applications

Multicast benefits

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

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 th e receivers treat th e multicast sources, the multicast m odels include any-source multicast (ASM), source-filtered multicast (SFM), and source-specific multicast (SSM).

ASM model

In the ASM model, any multicast sources can send infor mation to a multicast gr o up. R eceivers can join a multicast group and get multicast inform ation addressed to that multicast group from any

multicast sources. In this m odel, receivers do not know the positions of the multicast sources in

•

Address block

Description

maintenance, and so on. Table 3 lists com mon per mane nt

advance.

SFM model

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

The SFM model func tionall y extends t he ASM model. The upper-layer software c hecks the source address of received multicast pack ets and perm its or d enies m ulticast t raffic from specific sources. The receivers obtain the multicast data from only part of the multicast sources. To a receiver, multicast sources are not all valid, but are filtered.

SSM model

The SSM model provides a transmission service that enables multicast receivers to specify the multicast sources in which t he y are interes ted.

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, the SSM model uses a different multicast address r ange than the ASM/SFM model. Dedic ated 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 will provide data to the receivers? (Multicast source

discovery.)

How is the information 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

IP multicast addresses

IPv4 multicast addresses:

IANA assigned the Class D address block (224.0.0.0 to 239.255.255.255) to IPv4 multicast.

Table 2 Class D IP address blocks and description

224.0.0.0 to 224.0.0.255

Reserved permanent group addresses. The IP address

224.0.0.0 is reserved. Other IP addre sses can be use d by routing protocols and for topology searching, protocol

Address block

Description

group addresses. A packet destined for an address in this block will not be forw arded b eyond the l ocal subnet r egard les s

224.0.1.0 to 238.255.255.255

NOTE:

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.

Address

Description

•

239.0.0.0 to 239.255.255.255

of the 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 addr esses.

Administratively scoped multicast addresses. These addresses are considered locally unique rather than global ly unique. You can reuse them in domains administered by different organizations without causing conflicts. For more information, see RFC 2365.

Table 3 Common permanent multicast group addresses

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 All Core-Based Tree (CBT) routers.

224.0.0.16 Designated SBM.

224.0.0.17 All SBMs.

224.0.0.18 VRRP.

IPv6 multicast addresses:

Figure 4 IPv6 multicast format

Bit

Description

Value

Meaning

Group ID (112 bits)

0xFF

Flags

Scope

0 7 11 15 31

The following describes the fields of an IPv6 multicast address:

 0xFF—The most significant eight bits are 11111111.  Flags—The Flags field contains four bits.

Figure 5 Flags field format

Table 4 Flags field description

0 Reserved, set to 0.

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

• When set to 1, 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, this address is an IPv6 multicast address not based on a unicast prefix.

• When set to 1, this address is an IPv6 multicast address based on a un icast p refix . (The T bit must a lso be set to 1.)

• When set to 0, this address is an IPv6 multicast

address permanently-assigned by IANA.

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

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



internetwork for which the multicast traffic is intended.

Table 5 Values of the Scope field

0, F Reserved. 1 Interface-local scope. 2 Link-local scope. 3 Subnet-local scope. 4 Admin-local scope. 5 Site-local scope. 6, 7, 9 through D Unassigned. 8 Organization-local scope. E Global scope.

•

XXXX X

XXXX XXXX

1110 XXXX

0XXX XXXX

XXXX XXXX

0000 0001

0000 0000

0101 1110

32-bit IPv4 address

48-bit MAC address

5 bits lost

bit MAC address prefix

…

23 bits

mapped

…

FF1E 0000 0000 0000 0000 0000 F30E 0101

0101aF30E

48-bit MAC address

3333

32 bits

mapped

128-bit IPv6 address

… …

16-bit MAC

address prefix

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

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 an IPv4 multicast address.

Table 6 IPv4-to-MAC address mapping

The most significant four bits of an IPv4 multicast address are fixed at 1110. In an IPv4-to-MAC address mapping, five bits of the IPv4 multicast address are lost. As a result, 32 IPv4 multicast addresses are mapped to the same IPv4 multicast MAC address. A device might rec eive unwanted multicast data at Layer 2 processing, which needs to be filtered by the upper layer.

IPv6 multicast MAC addresses:

As defined by IANA, the most significant 16 bits of an IPv6 multicast MAC address are 0x3333. The least significant 32 bits are mapped from the least significant 32 bits of an IPv6 multicast address. Therefore, the problem of duplicate IPv6-to-MAC address mapping also arises like IPv4-to-MAC address mapping.

Table 7 IPv6-to-MAC address mapping

Multicast protoc ol s

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

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

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

•

AS 1 AS 2

Source

Receiver

PIM/IPv6 PIM

MBGP/MSDP

IPv6 MBGP

IGMP/MLD

IGMP

/MLD

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 o nly general descriptions a bout applications and f unc t ions 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 pro tocols include multicast group managem ent protocols and multicast routing protocols.

Figure 6 Positions of Layer 3 multicast protocols

Multicast group management protocols:

Multicast routing protocols:

Internet Group Management Protocol (IGMP) and Multicast Listener Discovery (MLD) protocol are multicast group management protocols. Typically, they run between hosts and Layer 3 multicast devices that directly connect to the hosts to establish and maintain multicast group memberships.

A multicast routing protocol runs on Layer 3 multicast devices to establish and maintain multicast routes and correctly and efficiently forward multicast packets. Multicast routes constitute loop-free data transmission paths (also known as multicast distribution trees) from a data source to multiple receivers.

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, 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 delivering multicast information

between two ASs. So far, mature solutions include Multicast Source Discovery Protocol (MSDP) and MBGP. MSDP propagates multicast source information among different ASs.

MBGP is an extension of the MP-BGP for exchanging multicast routing information among

•

IPv4/

IPv6 multicast packets (S1, G1)

IPv4/IPv6 multicast packets (S2, G2)

Source 1

Source 2

Receiver

IGMP Snooping /MLD Snooping

Receiver Receiver

Multicast VLAN

/IPv6 Multicast VLAN

PIM Snooping

IPv6 PIM Snooping

different ASs.

For the SSM model, multicast routes are not divided into intra-domain routes and inter-domain routes. Because receivers know the positions of the multicast sources, channels established through PIM-SM are sufficient for the transpor t 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 7 Positions of Layer 2 multicast pro to cols

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 Layer 2 networks.

PIM snooping and IPv6 PIM snooping:

PIM snooping and IPv6 PIM snooping run on Layer 2 devices. They work with IGMP snooping or MLD snooping to analyze received PIM messages. Then, they add the ports that are interested in specific multicast data to a PIM snooping routing entry or IPv6 PIM snooping routing 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:

Multicast VLAN or IPv6 multicast VLAN runs on a Layer 2 device in a multicast network where multicast receivers for the same group exist in different VLANs. With these protocols, 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 method avoids waste of network bandwidth and 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 areas on the network. They are ide ntified by the same m ulticast 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 forward

multicast packets that an incoming interface receives through multiple outgoing interfaces.

•

VPN A

VPN BVPN B

Public network

PE 1

PE 3

CE b3

CE a2

CE a3

CE b

CE a

CE b2

Compared to a unicast model, a multicast model is more complex in the following aspects:

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

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

T o process the same multicast information from different peers received on different interfaces,

the multicast device performs an RPF check on each multicast packet. The RPF check result determines whether the packet will be 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 VPNs.

Introduction to VPN instances

VPNs are isolated from one another and from the public network. As shown in Figure 8, VPN A and VPN B separately access the public network through PE devices.

Figure 8 VPN networking diagram

The P device belongs to the public network. The CE devices belong to their respective VPNs.

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

The 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.

For example, as shown in Figure 8, a multicast source in VPN A sends multicast data to a multicast group. Only receivers t hat belong t o both t he multicas t group and VPN A can receive the m ulticast data. The multicast data is multicast both in VPN A and on the public network.

Configuring IGMP snooping

Multicast packet transmission

without IGMP snooping

Source

Multicast router

Host A

Receiver

Host B

Host C

Receiver

Multicast packets

Layer 2

switch

Multicast packet transmission

when IGMP

snooping runs

Source

Multicast router

Host A

Receiver

Host B

Host C

Receiver

Layer 2 switch

Overview

IGMP snooping runs on a Layer 2 device as a multicast constraining mechanism to improve multicast forwarding efficiency. It creates La yer 2 multicast forwarding e ntries from IGMP packets that are exchanged between the hosts and the router.

As shown in Figure 9, when IGMP snooping is not enabled, the Layer 2 switch floods multicast packets to all hosts in a VLAN or VSI. When IGMP snooping is enabled, the Layer 2 switch forwards multicast packets of known multicast groups to only the receivers.

Figure 9 Multicast packet transmission without and with IGMP snooping

IGMP snooping ports

As shown in Figure 10, IGMP snooping runs on Switch A and Switch B, and Host A and Host C are receivers in a multicast group. IGMP snooping ports are divided into member ports and router ports.

Figure 10 IGMP snooping ports

•

Router A Switch A

Switch B

GE1/0/1 GE1/0/2

GE1/0/3

GE1

/0/2

Receiver

Host A

Host B

Host C

Host D

Source

Multicast packets

Router port

Member port

Router ports

On an IGMP snooping La yer 2 d evice, t he por ts to ward La yer 3 m ulticast d evices are c alled r outer ports. In Figure 10, GigabitEth ernet 1/0/1 of Switch A and GigabitEthernet 1/0/1 of Switc h B are router ports.

Router ports contain the following types:

Dynamic router port—When a port receives an IGMP general query whose source address is

not 0.0.0.0 or receives a PIM hello message, the port is added into the dynamic router port list. At the same time, an aging timer is started for the port. If the port receives either of the messages before the timer expires, the timer is reset. If the port does not receive either of the messages when the timer expires, the port is removed from the dynamic router port list.

Static router port—When a port is statically configured as a router port, it is added into the

static router port list. The static router port does not age out, and it can be deleted only manually.

Do not confuse th e "router port" i n IGMP snoop ing wit h the "rout ed inter face" co mmonl y known as the "Layer 3 interface." The router port in IGMP snooping is a Layer 2 interface.

Member ports

On an IGMP snooping Layer 2 device, the ports tow ard rece iver h osts are c alled m em ber ports . In

Figure 10, GigabitEthernet 1/0/2 and GigabitEthernet 1/0/3 of Switch A and GigabitEthernet 1/0/2 of

Switch B are member ports. Member ports contain the following types:

Dynamic member port—When a port receives an IGMP report, it is added to the associated

dynamic IGMP snooping forwarding entry as an outgoing interface. At the same time, an aging timer is started for the port. If the port receives an IGMP report before the timer expires, the timer is reset. If the port does not receive an IGMP report when the timer expires, the port is removed from the associated dynamic forwarding entry.

Static member port—When a port is statically configured as a member port, it is added to the

associated static IGMP snooping forwarding entry as an outgoing interface. The static member port does not age out, and it can be deleted only manually.

Unless otherwise spec if ied, router ports and member ports in this document include both static and dynamic router ports and member ports.

How IGMP snooping works

•

The ports in this section are dynamic ports. For information about how to configure and remove static ports, see "Configuring static ports."

IGMP messages types include general query, IGMP report, and leave message. An IGMP snooping-enabled Layer 2 device performs differently depending on the message types.

General query

The IG MP querier periodically sends IGM P general queries to all hosts and routers on th e local subnet to check for the existence of multicast group members.

After receiving an IGMP general query , the Layer 2 device forwards the query to all ports in the VLAN or VSI except the receiving port. The Layer 2 device also performs one of the following actions:

If the receiving port is a dynamic router port in the dynamic router port list, the Layer 2 device

restarts the aging timer for the port.

If the receiving port does not exist in the dynamic router port list, the Layer 2 device adds the

port to the dynamic router port list. It also starts an aging timer for the port.

IGMP report

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

Responds to queries if the host is a multicast group member. Applies for a multicast group membership.

After receiving an IGM P report from a host, the L ayer 2 device forw ards the report throu gh all the router ports in the VL AN or VSI. It also resol ves the address of the r eported multicast gr oup, and looks up the forwarding table for a matching entry as follows:

If no match is found, the Layer 2 device creates a forwarding entry with the receiving port as an

outgoing 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 matching forwarding entry does not contain the receiving port, the

Layer 2 device adds the receiving port to the outgoing interface list. It also marks the receiving port as a dynamic member port and starts an aging timer for the port.

If a match is found and the matching forwarding entry contains the receiving port, the Layer 2

device restarts the aging timer for the port.

In an application with a group policy configured on an IGMP snooping-enabled Layer 2 device, when a user requests a m ulticast program, the us er's host initiates an IG MP report. After receiving this report, the Layer 2 device resolves the multicast group address in the rep ort and performs ACL filtering on the report. If the report passes ACL filtering, the Layer 2 device creates an IGMP snooping forwarding entry for the multicast group with the receiving port as an outgoing interface. If the report does not pass ACL filtering, the Layer 2 device drops this report. The multicast data for the multicast group is not sent to this port, and the user cannot re trie ve the progr am.

A Layer 2 device does not forward an IGMP report thr ough a non-router p ort because of the host IGMP report suppression mechanism. For more information about the IGMP report suppression mechanism, see "Configuring IGMP."

Leave message

An IGMPv1 receiver host does not send any leave messages when it leaves a multicast group. The Layer 2 device cannot imm ediate ly update the s tatus of the por t that conn ects to the rec eiver host. The Layer 2 device does not remove the port from the outgoing interface list in the associated forwarding entry until the aging time for the group expires.

An IGMPv2 or IGMPv3 host sends an IGMP leave message when it leaves a multicast group. When the Layer 2 device receives an IGMP leave message on a dynamic member port, the Layer 2

device first examines whether a forwarding entry matches the group address in the message.

•

Host A

Receiver

Host B

Host C

Receiver

IGMP Querier

Router A

Proxy

Switch A

Query from Router A Report from Switch A Query from Switch A Report from Host

IP network

If no match is found, the Layer 2 device discards the IGMP leave message. If a match is found but the receiving port is not an outgoing interface in the forwarding entry , the

Layer 2 device discards the IGMP leave message.

If a match is found and the receiving port is not the only outgoing interface in the forwarding

entry, the Layer 2 device performs the following actions:

 Discards the IGMP leave message.  Sends an IGMP group-specific query to identify whether the group has active receivers

attached to the receiving port.

 Sets the aging timer for the receiving port to twice the IGMP last member query interval.

If a match is found and the receiving port is the only outgoing interface in the forwarding entry,

the Layer 2 device performs the following actions:

 Forwards the IGMP leave message to all router ports in the VLAN or VSI.  Sends an IGMP group-specific query to identify whether the group has active receivers

attached to the receiving port.

 Sets the aging timer for the receiving port to twice the IGMP last member query interval.

After receiving the IGMP leave mes sage on a port, the IGMP querier resol ves the multicast group address in the message. Then, it sends an IGMP group-specific query to the multicast group through the receiving port.

After receiving the IGM P group-specific query, the Layer 2 device f orwards the query through all router ports and mem ber ports of the group in the VLAN or V SI. Then, it waits for the respon ding IGMP report from the directly connected hosts. For the dynamic member port that received the leave message, the Layer 2 device also performs one of the following actions:

If the port receives an IGMP report before the aging timer expires, the Layer 2 device resets the

aging timer.

If the port does not receive an IGMP report when the aging timer expires, the Layer 2 device

removes the port from the forwarding entry for the multicast group.

IGMP snooping proxying

As shown in Figure 11, to reduce the number of IGMP reports and leave messages received by the upstream device, you can enable IGM P snooping prox ying on the edge device . The edge device then acts as a host to send IGMP reports and leave messages to Router A.

An edge device enabled with IGMP snooping proxying does not support the host IGMP report suppression mechanism. For more information about the IGMP report suppression mechanism, see "Configuring IGMP."

Figure 11 IGMP snooping proxying

•

The IGMP snooping proxy device processes different IGMP messages as follows:

General query.

After receiving an IGMP general query, the device forwards the query to all ports in the VLAN except the receiving port. The device also generates an IGMP report based on the local membership information and sends the report to all router ports.

Group-specific query or group-and-source-specific query.

After receiving an IGMP group-specific query or group-and-source-specific query, the device forwards the query to all router ports in the VLAN except the receiving port. If the forwarding entry has a member port, the device sends a report to all router ports in the VLAN.

Report.

After receiving an IGMP report from a host, the devic e looks up the forwarding table for a matching entry as follows:

 If a match is found and the matching forwarding entry contains the receiving port, the device

resets the aging timer for the port.

 If a match is found but the matching forwarding entry does not contain the receiving port, the

device adds the receiving port to the outg oin g interface list. It also marks the receiving port as a dynamic member port and starts an aging timer for the port.

 If no match is found, the device creates a forwarding entry with the receiving port as an

outgoing interface. It also marks the receiving port as a dynamic member port and starts an aging timer for the port. Then it sends the report to all router ports.

Leave message.

After receiving an IGMP leave message on a port, the device sends an IGMP group-specific query through the receiving port. The device sends the IGMP leave message to all router ports only when the last member port is removed from the forwarding entry.

Protocols and standards

RFC 4541, Considerat ions for Internet G ro up Man agement Protoc ol ( IG MP) and Multicast Lis tener Discovery (MLD) Snooping Switches

Configuration restrictions and guidelines

When you configure IGMP snooping, follow these restrictions and guidelines:

If you change the VPN instance bound to the VLAN interface of a VLAN, Layer 2 multicast traffic

in the VLAN is interrupted. To allow new IGMP snooping forwarding entries to be created, execute the reset igmp-snooping group command.

For IGMP reports received from secondary VLANs, the relevant IGMP snooping forwarding

entries are maintained by the primary VLAN. Therefore, you need to enable IGMP snooping only for the primary VLAN. The IGMP snooping configuration made in secondary VLANs does not take effect. For more information about primary VLANs and secondary VLANs, see Layer 2—LAN Switching Configuration Guide.

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 configuration made on a member port of the aggregate group takes effect after the port leaves the aggregate group.

IGMP snooping configuration task list

You can configure IGMP snooping for VLANs or VSIs.

IGMP snooping configuration t as k list for VLANs

Tasks at a glance

Configuring basic IGMP snooping features:

• (Required.) Enabling IGMP snooping

• (Optional.) Specifying an IGMP snooping version

• (Optional.) Setting the maximum number of IGMP snooping forwarding entries

• (Optional.) Configuring static multicast MAC address entries

• (Optional.) Setting the IGMP last member query interval

Configuring IGMP snooping port features:

• (Optional.) Setting aging timers for dynamic ports

• (Optional.) Configuring static ports

• (Optional.) Configuring a port as a simulated member host

• (Optional.) Enabling fast-leave processing

• (Optional.) Disabling a port from becoming a dynamic router port

Configuring the IGMP snooping querier:

• (Optional.) Enabling the IGMP snooping querier

• (Optional.) Configuring parameters for IGMP general queries and responses

(Optional.) Enabling IGMP snooping proxying

Configuring parameters for IGMP messages:

• (Optional.) Configuring the source IP address for IGMP messages

• (Optional.) Setting the 802.1p priority for IGMP messages

Configuring IGMP snooping policies:

• (Optional.) Configuring a multi cast group policy

• (Optional.) Enabling multicast source port filtering

• (Optional.) Enabling dropp ing unknown multicast data

• (Optional.) Enabling IGMP report suppression

• (Optional.) Setting the maximum number of multicast groups on a port

• (Optional.) Enabling mul tic ast group r epl ace men t

• (Optional.) Enabling host tracking

IGMP configuration task list for VSIs

Configuring basic IGMP snooping features:

• (Required.) Enabling IGMP snooping

• (Optional.) Specifying an IGMP snooping version

• (Optional.) Setting the maximum number of IGMP snooping forwarding entries

• (Optional.) Setting the IGMP last member query interval

Configuring IGMP snooping port features:

• (Optional.) Setting aging timers for dynamic ports

Configuring the IGMP snooping querier:

• (Optional.) Enabling the IGMP snooping querier

• (Optional.) Configuring parameters for IGMP general queries and responses

Configuring parameters for IGMP messages:

• (Optional.) Configuring the source IP address for IGMP messages

Tasks at a glance

• (Optional.) Setting the 802.1p priority for IGMP messages

Configuring IGMP snooping policies:

•

Step

Command

Remarks

Step

Command

Remarks

By default, IGMP snooping is

• (Optional.) Enabling dropp ing unknown multicast data

• (Optional.) Enabling mul tic ast group r epl ace men t

Configuring basic IGMP snooping features

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

Configure VLANs or VSIs. Determine the IGMP snooping version. Determine the maximum number of IGMP snooping forwarding entries. Determine the IGMP last member query interval.

Enabling IGMP s nooping

When you enable IGMP snooping, follow these restrictions and guidelines:

You must enable IGMP snooping globally before you enable it for a VLAN or VSI. IGMP snooping configuration made in VLAN or VSI view takes effect only on the member ports

in that VLAN or VSI.

You can enable IGMP snooping for the specified VLANs in IGMP-snoopi ng vi e w, for a VSI in

VSI view, or for a VLAN in VLAN view. For a VLAN, the configuration in VLAN view has the same priority as the configuration in IGMP-snooping view, and the most recent configuration takes effect.

Enabling IGMP snooping in IGMP-snooping view

1. Enter system view.

2. Enable IGMP snooping

globally and enter IGMP-snooping view.

3. Enable IGMP snooping for the specified VLANs.

system-view

igmp-snooping

enable vlan

vlan-list

Enabling IGMP snooping in VLAN or VSI view

1. Enter system view.

2. Enable IGMP snooping

globally and enter IGMP-snooping view.

3. Return to system view.

4. Enter VLAN view or VSI

view.

system-view

igmp-snooping

quit

• Enter VLAN view: vlan vlan-id

• Enter VSI view:

vsi vsi-name

N/A By default, IGMP snooping is

globally disabled. By default, IGMP snooping is

disabled for a VLAN.

N/A By default, IGMP snooping is

globally disabled.

N/A

Enable IGMP snooping for

igmp-snooping enable

Step

Command

Remarks

the VLAN or VSI.

disabled in a VLAN or VSI.

•

Step

Command

Remarks

Step

Command

Remarks

Specifying an IGMP snooping version

Different IGMP snooping versions process different versions of IGMP messages.

IGMPv2 snooping processes IGMPv1 and IGMPv2 messages, but it floods IGMPv3 messages

in the VLAN instead of processing them.

IGMPv3 snooping processes IGMPv1, IGMPv2, and IGMPv3 messages.

If you change IGMPv3 snooping to IGMPv2 snooping, the device performs the following actions:

Clears all IGMP snooping forwarding entries that are dynamicall y 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 IGMP snooping forwarding entries, see "Configuring static ports." Y ou can specify the version for the specified VLANs in IGMP-snooping view, for a VSI in VSI view, or

for a VLAN in VLAN v ie w. For a VLAN, the c onf igura ti on i n V LA N v ie w has t he same priority as the configuration in IGMP-snooping view, and the most recent configuration takes effect.

Specifying an IGMP snooping version in IGMP-snooping view

1. Enter system view.

2. Enable IGMP snooping

globally and enter IGMP-snooping view.

3. Specify an IGMP snooping version for the specified VLANs.

system-view

igmp-snooping

version

vlan-list

version-number

vlan

N/A

The default setting is 2.

Specifying an IGMP snooping version in VLAN or VSI view

1. Enter system view.

2. Enter VLAN view or VSI view.

3. Specify an IGMP snooping

version for the VLAN or VSI.

system-view

• Enter VLAN view:

vlan vlan-id

• Enter VSI view:

vsi vsi-name

igmp-snooping version

version-number

N/A

The default setting is 2.

Setting the maximum number of IGMP s noopi ng forwarding entries

You can modify the maximum number of IGMP snooping forwarding entries, including dynamic entries and static entr ies. W hen the number of forwardin g entries on the de vice reaches the upper limit, the device does not automatically remove any existing entries. To allow new entries to be created, remove some entries manually.

To set the maximum number of IGMP snooping forwarding entries:

Step

Command

Remarks

system-view

igmp-snooping

•

Step

Command

Remarks

Step

Command

Remarks

1. Enter system view.

2. Enter IGMP-snooping view.

3. Set the maximum number of

IGMP snooping forwarding entries.

entry-limit

limit

N/A N/A

The default setting is

4294967295.

Configuring static multicast MAC address entries

In Layer 2 multicast, m ulticast MAC address entries can be dynamically created t hrough Layer 2 multicast protocols (such as IGMP snooping). Y ou can also manually configure static multicast MAC address entries by binding multicast MAC addresses and ports to control the destination ports of the multicast data.

Configuration restrictions and guidelines

When you configure static multicast MAC address entries, follow these restrictions and guidelines:

You do not need to enable IP multicast routing before this configuration. Y ou must specify an unused multicast MAC address for a static multicast MAC address entry. A

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

Y ou can configure a static multicast MAC address entry for multiple interfaces in system view, or

for the current interface in interface view.

Configuring a static multicast MAC address entry in system view

1. Enter system view.

2. Configure a static multicast

MAC address entry.

system-view mac-address multicast

mac-address interface-list

interface

vlan

vlan-id

N/A

By default, no static multicast MAC address entries exist.

Configuring a static multicast MAC address entry in interface view

1. Enter system view.

2. Enter Layer 2 Ethernet

interface or Layer 2 aggregate interface view.

3. Configure a static multicast MAC address entry.

system-view

interface

interface-number

mac-address multicast

mac-address

interface-type

vlan

vlan-id

N/A

By default, no static multicast MAC address entries exist.

Setting the IGMP las t member query interval

A receiver host starts a report delay timer for a multicast group when it receives an IGMP group-specific query for the group. This timer is set to a random value in the range of 0 to the maximum response tim e advertised in the query. When the timer value decreases to 0, the host sends an IGMP report to the group.

The IGMP last member query interval defines the maximum response time advertised in IGMP

•

Step

Command

Remarks

igmp-snooping

Step

Command

Remarks

•

group-specific queries. Set an ap propriate va lue for th e IGMP last m ember quer y interval to spe ed up hosts' responses to IGMP group-specific queries and avoid IGMP report traffic bursts.

Configuration restrictions and guidelines

When you set the IGMP last member query interval, follow these restrictions and guidelines:

The Layer 2 device does not send an IGMP group-specific query if it receives an IGMP leave

message from a port enabled with fast-leave processing.

You can set the IGMP last member quer y interval glob ally for all VLANs and VSIs in

IGMP-snooping view, for a VSI in VSI view, or for a VLAN in VLAN view. For a VLAN, the VLAN-specific configuration takes priority over the global configuration. For a VSI, the VSI-specific configuration takes priority over the global configuration.

Setting the IGMP last member query interval globally

1. Enter system view.

2. Enter IGMP-snooping view.

3. Set the IGMP last member

query interval globally.

system-view

last-member-query-interval

interval

N/A N/A The default setting is 1

second.

Setting the IGMP last member query interval in a VLAN or VSI

1. Enter system view.

2. Enter VLAN view or VSI view.

3. Set the IGMP last member

query interval for the VLAN or VSI.

system-view

• Enter VLAN view: vlan vlan-id

• Enter VSI view:

vsi vsi-name

igmp-snooping last-member-query-interval

interval

N/A

The default setting is 1 second.

Configuring IGMP snooping port features

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

Enable IGMP snooping for the VLAN or VSI. Determine the aging timer for dynamic router ports. Determine the aging timer for dynamic member ports. Determine the addresses of the multicast group and multicast source.

Setting aging tim er s for dynamic port s

When you set aging timers for dynamic ports, follow these restrictions and guidelines:

If the memberships of multicast groups frequently change, you can set a relatively small value

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

If a dynamic router port receives a PIMv2 hello message, the aging timer for the port is specified

by the hello message. In this case, the router-aging-time or igmp-snooping router-aging-time command does not take effect on the port.

•

Step

Command

Remarks

system-view

Step

Command

Remarks

•

Step

Command

Remarks

interface

interface-type

IGMP group-specific queries originated by the Layer 2 device trigger the adjustment of aging

timers for dynamic member ports. If a dynamic member port receives such a query, its aging timer is set to twice the IGMP last member query interval. For more information about setting the IGMP last member query interval on the Layer 2 device, see "

query interval."

You can set the timers globally for all VLANs and VSIs in IGMP-snooping view, for a VSI in VSI

view, or for a VLAN in VLAN view. For a VLAN, the VLAN-specific configuration takes priority over the global configuration. For a VSI, the VSI-specific configuration takes priority over the global configuration.

Setting the aging timers for dynamic ports globally

Setting the IGMP last member

1. Enter system view.

2. Enter IGMP-snooping view.

3. Set the aging timer for

dynamic router ports globally.

4. Set the global aging timer for dynamic member ports globally.

igmp-snooping

router-aging-time

host-aging-time

seconds

Setting the aging timers for dynamic ports in a VLAN or VSI

1. Enter system view.

2. Enter VLAN view or VSI

view.

3. Set the aging timer for dynamic router ports in the VLAN or VSI.

4. Set the aging timer for dynamic member por ts in t he VLAN or VSI.

system-view

• Enter VLAN view: vlan vlan-id

• Enter VSI view:

vsi vsi-name

igmp-snooping router-aging-time

igmp-snooping host-aging-time

seconds

N/A N/A

The default setting is 260 seconds.

N/A

The default setting is 260 seconds.

Configuring static ports

You can configure the following types of static ports:

Static member port—When you configure a port as a static member port for a multicast group,

all hosts attached to the port will receive multicast data for the group. The static member port does not respond to IGMP queries. When you complete or cancel this

configuration on a port, the port does not send an unsolicited IGMP report or leave message.

Static router port—When you configure a port as a static router port for a multicast group, all

multicast data for the group received on the port will be forwarded.

To configure a port as a static port:

1. Enter system view. Enter Layer 2 Ethernet

system-view

N/A N/A

Step

Command

Remarks

interface view or Layer 2

aggregate interface view.

interface-number

•

Step

Command

Remarks

•

• Configure the port as a static

member port: igmp-snooping static-group group-address

3. Configure the port as a static

port.

[ source-ip source-address ] vlan vlan-id

• Configure the port as a static router port:

igmp-snooping static-router-port vlan

vlan-id

By default, a port is not a static member port or a static router port.

Configuring a port as a simulated member host

When a port is configured as a simulated member host, it is equivalent to an independent host in the following wa ys:

It sends an unsolicited IGMP report when you complete the configuration. It responds to IGMP general queries with IGMP reports. It sends an IGMP leave message when you cancel the configuration.

The version of IGMP run ning on the simulated member host is the sam e as the version of IGMP snooping running on the port. The port ages out in the same way as a dynamic member port.

To configure a port as a simulated member host:

1. Enter system view.

2. Enter Layer 2 Ethernet

interface view or Layer 2 aggregate interface view.

3. Configure the port as a simulated member host.

system-view

interface

interface-number

igmp-snooping host-join

group-address [ source-address ]

interface-type

Enabling fast-leave processin g

This feature enables the device to immediately remove a port from the forwarding entry for a multicast group when the port receives a leave massage.

Configuration restrictions and guidelines

When you enable fast-leave processing, follow these restrictions and guidelines:

Do not enable fast-leave processing on a port that has multiple receiver hosts in a VLAN. If

fast-leave processing is enabled, the remaining receivers cannot receive multicast data for a group after a receiver leaves that group.

You can enable fast-lea ve proc ess ing globally for all ports in IGMP-snooping view or for a port

in interface view. For a port, the port-specific configuration takes priority over the global configuration.

source-ip

vlan

vlan-id

N/A

By default, the port is not a simulated member host.

Enabling fast-leave processing globally

Step

Command

Remarks

Step

Command

Remarks

•

Step

Command

Remarks

1. Enter system view.

2. Enter IGMP-snooping view.

3. Enable fast-leave proces sing

globally.

system-view igmp-snooping

fast-leave [ vlan

vlan-list ]

N/A N/A By default, fast-leave processing

is disabled globally.

Enabling fast-leave processing on a port

1. Enter system view.

2. Enter Layer 2 Ethernet

interface view or Layer 2 aggregate interface view.

3. Enable fast-leave proces sing on the port.

system-view

interface

interface-number

igmp-snooping fast-leave [ vlan

vlan-list ]

interface-type

N/A

By default, fast-leave processing is disabled on a port.

Disabling a port from becoming a dynam ic router port

A receiver host might send IGMP general queries or PIM hello m essages for tes ting purposes. On the Layer 2 device, t he port that rec eives either of the messages bec omes a dynam ic router port. Before the aging timer for the port expires, the following problems might occur:

All multicast data for the VLAN to which the port belongs flows to the port. Then, the port

forwards the data to attached receiver hosts. The receiver hosts will receive multicast data that it does not want to receive.

The port forwards the IGMP general queries or PIM hello messages to its upstream multicast

routers. These messages might affect the multicast routing protocol state (such as the IGMP querier or DR election) on the multicast routers. This might further cause network interruption.

To solve these problems, you can disable a port from becoming a dynamic rout er port. This also improves network security and the control over receiver hosts.

To disable a port from becoming a dynamic router port:

1. Enter system view.

2. Enter Layer 2 Ethernet

interface view or Layer 2 aggregate interface view.

3. Disable the port from becoming a dynamic router port.

system-view

interface

interface-number

igmp-snooping router-port-deny [ vlan

interface-type

vlan-list ]

N/A

By default, a port is allowed to become a dynamic router port.

This configuration does not affect the static router port conf iguration.

Configuring the IGMP snooping querier

This section describes how to configure an IGMP snooping querier.

Configuration prerequisites

•

Step

Command

Remarks

CAUTION:

To avoid mistakenly deleting multicast group members, make sure

interval

is greater than the maximum response time for IGMP general queries .

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

Enable IGMP snooping for the VLAN or VSI. Determine the IGMP general query interval. Determine the maximum response time for IGMP general queries.

Enabling the IGMP snooping querier

This feature enables the device to periodically send IGMP general queries to establish and maintain multicast forwarding entries at the data link Layer. You can configure an IGMP snooping querier on a network without Layer 3 multicast devices.

Configuration restrictions and guidelines

When you enable the IGMP snooping querier, follow these restrictions and guidelines:

Do not enable the IGMP snooping querier on 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 if it sends IGMP general queries with a low source IP address.

On a VXLAN network, the IGMP snooping querier in a VSI does not include VLAN tags in IGMP

general queries. As a best practice, do not enable the IGMP snooping querier in a VSI if the VSI uses the Ethernet access mode. For more information about the Ethernet access mode, see VXLAN Configuration Guide.

Configuration procedure

To enable the IGMP snooping querier for a VLAN or VSI:

1. Enter system view.

2. Enter VLAN view or VSI

view.

3. Enable the IGMP snooping querier.

system-view

• Enter VLAN view: vlan vlan-id

• Enter VSI view:

vsi vsi-name

igmp-snooping querier

N/A

By default, the IGMP snooping querier is disabled.

Configuring pa rameters for IGMP general queries and responses

You can modify the IGMP general query interval for a VLAN or VSI based on the actual condition of the network.

the IGMP general query

A receiver host starts a report delay timer for each multicast group that it has joined when it receives an IGMP general query. This timer is set to a random value in t he range of 0 to the maximum response time advertised in the query. When the timer value decreases to 0, the host sends an IGMP report to the corresponding multicast group.

Set an appropriate value for the maximum response tim e for IGMP general queries to sp eed up

Step

Command

Remarks

Step

Command

Remarks

Step

Command

Remarks

hosts' responses to IG M P general queries and avoid IGMP report traffic bursts. Y ou can set the maximum response time for IGMP general queries globally for all VLANs and VSIs in

IGMP-snooping view, for a VSI in VSI view, or for a VLAN in VLAN view. For a VLAN, the VLAN-specific conf iguration tak es prior ity over th e global c onfigurat ion. For a VSI, the VSI-specific configuration takes priority over the global configuration.

Configuring parameters for IGMP general queries and responses globally

1. Enter system view.

2. Enter IGMP-snooping view.

3. Set the maximum response

time for IGMP general queries.

system-view igmp-snooping

max-response-time

seconds

N/A N/A

The default setting is 10 seconds.

Configuring parameters for IGMP general queries and responses in a VLAN or VSI

1. Enter system view.

2. Enter VLAN view or VSI

view.

3. Set the IGMP general query interval in the VLAN or VSI.

4. Set the maximum response time for IGMP general queries in the VLAN or VSI.

system-view

• Enter VLAN view:

vlan vlan-id

• Enter VSI view:

vsi vsi-name

igmp-snooping query-interval

interval

igmp-snooping max-response-time

seconds

N/A

The default setting is 125 seconds.

The default setting is 10 seconds.

Enabling IGMP snooping proxying

Before you enable IGMP snooping proxying for a VLAN, enable IGMP snooping for the VLAN. To enable IGMP snooping proxying:

1. Enter system view.

2. Enter VLAN view.

3. Enable IGMP snooping

proxying for the VLAN.

system-view vlan

vlan-id

igmp-snooping proxy enable

N/A N/A By default, IGMP snooping

proxying is disabled for a VLAN.

Configuring parameters for IGMP messages

This section describes how to configure parameters for IGMP messages.

Configuration prerequisites

Before you configure parameters for IGMP messages, complete the following tasks:

•

Step

Command

Remarks

6. Configure the source IP

igmp-snooping leave

By default, the source IP address of

Enable IGMP snooping for the VLAN or VSI. Determine the source IP address of IGMP general queries. Determine the source IP address of IGMP group-specific queries. Determine the source IP address of IGMP reports. Determine the source IP address of IGMP leave messages. Determine the 802.1p priority of IGMP messages.

Configuring the source IP address for IGMP messages

The IGMP snooping querie r might send IGMP general queries with the sourc e IP address 0.0. 0.0. The port that receives such queries will not be maintained as a d ynamic router port . This might prevent the associated dynamic IGMP snooping forwarding entry from being correctly created at the data link layer and eventually cause multicast traffic forwarding failures.

To avoid this problem, you can conf igure a non-all-zero IP address as the s ource IP address of the IGMP queries on the IGMP snooping querier. This configuration might affect the IGMP querier election within the subnet.

You can also change the source IP address of IGMP reports or leave messages sent by a simulated member host or an IGMP snooping proxy.

Configuring the source IP address for IGMP messages in a VLAN

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

vlan-id

igmp-snooping general-query source-ip

ip-address

igmp-snooping special-query source-ip

ip-address

N/A N/A By default, the source IP address of

IGMP general queries is the IP address of the current VLAN int erface. If the current VLAN interface does not have an IP address, the source IP address is 0.0.0.0.

By default, the source IP address of IGMP group-specific queries is one of the following:

• The source address of IGMP group-specific queries if the IGMP snooping querier of the VLAN has received IGMP general queries.

• The IP address of the current VLAN interface if the IGMP snooping querier does not receive an IGMP general query.

• 0.0.0.0 if the IGMP snooping querier does not receive an IGMP general query and the current VLAN interface does not have an IP address.

5. Configure the source IP address for IGMP reports.

igmp-snooping report source-ip

ip-address

By default, the source IP address of IGMP reports is the IP address of the current VLAN interface. If the current VLAN interface does not have an IP address, the source IP address is

0.0.0.0.

Step

Command

Remarks

address for IGMP leave

messages.

source-ip

ip-address

IGMP leave messages is the IP

Step

Command

Remarks

Configuring the source IP address for IGMP messages in a VSI

address of the current VLAN int erface. If the current VLAN inter f ac e does not have an IP address, the source IP address is 0.0.0.0.

1. Enter system view.

2. Enter VSI view.

3. Configure the source IP

address for IGMP general queries.

4. Configure the source IP address for IGMP group-specific queries.

5. Configure the source IP address for IGMP reports.

system-view vsi

vsi-name

igmp-snooping general-query source-ip

ip-address

igmp-snooping special-query source-ip

ip-address

igmp-snooping report source-ip

ip-address

N/A N/A By default, the source IP address of

IGMP general queries is the IP address of the gateway interface for a VSI. If the gateway interface does not have an IP address, the source IP address is 0.0.0.0.

By default, the source IP address of IGMP group-specific queries is one of the following:

• The source IP address of IGMP general queries if the IGMP snooping querier of a VSI has received IGMP general queries.

• The IP address of the gateway interface for the VSI if the IGMP snooping querier does not receive an IGMP general query.

• 0.0.0.0 if the gatew ay interface of the VSI does not have an IP address.

By default, the source IP address of IGMP reports is the IP address of the gateway interface for a VSI. If the gateway interface doe s not have an I P address, the source IP address is

0.0.0.0.

6. Configure the source IP

Setting the 802. 1p pr i ority for IGMP mes sages

When congestion occurs on outgoing ports of the Layer 2 device, it forwards IGMP messages in their

802.1p priority order, from highest to lowest. You can assign a higher 802.1p priority to IGMP messages that are created or forwarded by the device.

Y ou can set the 802.1p priority globally for all VLANs and VSIs in IGMP-snooping view or for a VLAN in VLAN view. For a VLAN, the VLAN-specific configuration takes priority over the global configuration.

address for IGMP leave messages.

igmp-snooping leave source-ip

ip-address

By default, the source IP address of IGMP leave messages is the IP address of the gateway interface for a VSI. If the gateway interface does not have an IP address, the source IP address is 0.0.0.0.

Setting the 802.1p priority for IGMP messages globally

Step

Command

Remarks

Step

Command

Remarks

•

Step

Command

Remarks

1. Enter system view.

2. Enter IGMP-snooping view.

3. Set the 802.1p priority for

IGMP messages.

system-view igmp-snooping

dot1p-priority

priority

N/A N/A By default, the 802.1p priority for

IGMP packets is not configured.

Setting the 802.1p priority for IGMP messages in a VLAN

1. Enter system view.

2. Enter VLAN view.

3. Set the 802.1p priority for

IGMP messages in the VLAN.

system-view vlan

vlan-id

igmp-snooping dot1p-priority

priority

N/A N/A

By default, the 802.1p priority for IGMP packets is not configured.

Configuring IGMP snooping policies

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

Enable IGMP snooping for the VLAN or VSI. Determine the ACL used by the multicast group policy. Determine the maximum number of multicast groups that a port can join.

Configuring a multicast group policy

This feature enables the devic e to filter IGM P reports b y using an ACL that spec ifies the m ulticast groups and the optional sources. It is used to control the multicast groups that hosts can join.

Configuration restrictions and guidelines

When you configure a multicast group policy, follow these restrictions and guidelines:

This configuration takes effect only on the multicast groups that ports join dynamically. You can configure a multicast group policy globally for all ports in IGMP-snooping view or for a

port in interface view. For a port, the port-specific configuration takes priority over the global configuration.

Configuring a multicast group policy globally

1. Enter system view.

2. Enter IGMP-snooping view.

3. Configure a multicast group

policy globally.

system-view igmp-snooping

group-policy

vlan

[

ipv4-acl-number

vlan-list ]

N/A N/A By default, no multicast group

policies exist, and hosts can join any multicast groups.

Configuring a multicast group policy on a port

Step

Command

Remarks

Step

Command

Remarks

system-view

igmp-snooping

Step

Command

Remarks

•

1. Enter system view.

2. Enter Layer 2 Ethernet

interface view or Layer 2 aggregate interface view.

3. Configure a multicast group policy on the port.

system-view

interface

interface-number

igmp-snooping group-policy

ipv4-acl-number [

interface-type

vlan

vlan-list ]

Enabling multicast source port f i ltering

This feature enables the device to discard all multicast data packets and to accept multicast protocol packets. You can enable this feature on ports that connect only to multicast receivers.

You can enable this f eature for the specifie d ports in IGMP -snoopi ng view or for a port in interf ace view. For a port, the configuration in interface view has the sam e priority as the configuration in IGMP-snooping view, and the most recent configuration takes effect.

Enabling multicast source port filtering in IGMP-snooping view

1. Enter system view.

2. Enter IGMP-snooping view.

3. Enable multicast source port

filtering.

source-deny port

interface-list

N/A

By default, no multicast group policies exist on a port, and hosts attached to the port can join any multicast groups.

N/A N/A By default, multicast source port

filtering is disabled.

Enabling multicast source port filtering in interface view

1. Enter system view.

2. Enter Layer 2 Ethernet

interface view.

3. Enable multicast source port filtering.

system-view interface

interface-number

igmp-snooping source-deny

interface-type

Enabling dropping unknown multicas t data

This feature enables the device to drop all unknown multicast data. Unknown multicast data refers to multicast data for which no forwarding entries exist in the IGMP snooping forwarding table.

If you do not enable this feature, the unknown multicast data is flooded in the VLAN to which the data belongs.

Configuration restrictions and guidelines

When you enable dropping unknown multicast data, follow these restrictions and guidelines:

Y ou can enable this feature globally for all VLANs in IGMP-snooping view, for a VSI in VSI view,

or for a VLAN in VLAN view.

The configuration made in IGMP-snooping view takes effect only on all VLANs. It does not take

effect on VSIs.

N/A

By default, multicast source port filtering is disabled.

•

Step

Command

Remarks

Step

Command

Remarks

Step

Command

Remarks

•

The drop-unknown and igmp-snooping drop-unknown commands are mutually exclusive.

You cannot configure them on the same device.

The device still forwards unknown IPv4 multicat data to router ports (excluding the incoming

port) in a VLAN or VSI even though this feature is enabled.

Enabling dropping unknown multicast data globally

1. Enter system view.

2. Enter IGMP-snooping view.

3. Enable dropping unknown

multicast data globally.

system-view igmp-snooping

drop-unknown

Enabling dropping unknown multicast data in a VLAN or VSI

1. Enter system view.

2. Enter VLAN view or VSI

view.

3. Enable dropping unknown multicast data for the VLAN or VSI.

system-view

• Enter VLAN view:

vlan vlan-id

• Enter VSI view:

vsi vsi-name

igmp-snooping drop-unknown

Enabling IGMP report suppression

N/A N/A By default, dropping unknown

multicast data is disabled, and unknown multicast d ata is flooded.

N/A

By default, dropping unknown multicast data is disabled, and unknown multicast d ata is flooded.

This feature en ables the device to forward onl y the first IGMP report for a multicast gr oup to its directly connected L ayer 3 device. Other repor ts f or the sam e gr oup in th e sam e quer y interv al are discarded. Use this feature to reduce multicast traffic.

To enable IGMP report suppression:

1. Enter system view.

2. Enter IGMP-snooping view.

3. Enable IGMP report

suppression.

system-view igmp-snooping

report-aggregation

N/A N/A By default, IGMP report

suppression is enabled.

Setting the maximum number of multicast groups on a port

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

Configuration restrictions and guidelines

When you set the maximum number of multicast groups on a port, follo w these restrictio ns and guidelines:

This configuration takes effect only on the multicast groups that a port joins dynamically.

•

Step

Command

Remarks

•

Step

Command

Remarks

Step

Command

Remarks

If the number of multicast groups on a port exceeds the limit, the system removes all the

forwarding entries related to that port. The receiver hosts attached to that port can join multicast groups again before the number of multicast groups on the port reaches the limit.

Configuration procedure

To set the maximum number of multicast groups on a port:

1. Enter system view.

2. Enter Layer 2 Ethernet

interface view or Layer 2 aggregate interface view.

3. Set the maximum number of multicast groups on a port.

system-view

interface

interface-number

igmp-snooping group-limit

vlan

[

interface-type

vlan-list ]

Enabling multicast group replacement

This feature enables th e device to rep lace an existing group with a newly joined group when the number of groups exc eeds the upper limit. This feature is t ypically used in the channel switchi ng application. W ithout this feature, the device discards IGMP reports for new groups, and the user cannot change to the new channel.

Configuration restrictions and guidelines

When you enable multicast group replacement, follow these restrictions and guidelines:

This configuration takes effect only on the multicast groups that a port joins dynamically. Y ou can enable this feature globally for all ports in IGMP-snooping view or for a port in interface

view. For a port, the port-specific configuration takes priority over the global configuration.

Enabling multicast group replacement globally

limit

N/A

By default, no limit is placed on the maximum number of multicast groups on a port.

1. Enter system view.

2. Enter IGMP-snooping view.

3. Enable multicast group

replacement globally.

system-view igmp-snooping

overflow-replace [ vlan

Enabling multicast group replacement on a port

1. Enter system view.

2. Enter Layer 2 Ethernet

interface view or Layer 2 aggregate interface view.

3. Enable multicast group replacement on a port.

system-view

interface

interface-number

igmp-snooping overflow-replace [ vlan

interface-type

vlan-list ]

N/A N/A By default, multicast group

replacement is disabled globally .

N/A

By default, multicast group replacement is disabled on a port.

Enabling host trac k i ng

Step

Command

Remarks

Step

Command

Remarks

vlan

Task

Command

source-address ] * [

vlan

vlan-id ] [

verbose

] [

chassis

This feature enables the device to record information about member hosts that are receiving multicast data. The information includes IP addresses of the hosts, length of time elapsed since the hosts joined multicast groups, and remaining timeout time for the hosts. This feature facilitates monitoring and managing member hosts.

Enabling host tracking globally

1. Enter system view.

2. Enter IGMP-snooping view.

3. Enable host tr acking global ly .

system-view igmp-snooping

host-tracking

N/A N/A By default, host tracking is

disabled globally.

Enabling host tracking in a VLAN

1. Enter system view.

2. Enter VLAN view.

3. Enable host tracking for the

VLAN.

system-view

vlan-id

igmp-snooping host-tracking

N/A N/A By default, host tracking is

disabled for a VLAN.

Displaying and maintaining IGMP snooping

Execute display commands in any view and reset commands in user view.

Display IGMP snooping status.

display igmp-snooping

global

[

vlan

vlan-id |

vsi

vsi-name ]

(In standalone mode.) Display dynamic IGMP snooping group entries.

(In IRF mode.) Display dynamic IGMP snooping group entries.

(In standalone mode.) Display host tracking information.

(In IRF mode.) Display host tracking information.

(In standalone mode.) Display dynamic router port information.

(In IRF mode.) Display dynamic router port information.

(In standalone mode.) Display static IGMP snooping group entries.

(In IRF mode.) Display static IGMP snooping group entries.

display igmp-snooping group

source-address ] * [

slot

[

slot-number ]

display igmp-snooping group

source-address ] * [

chassis

[

display igmp-snooping host-tracking vlan

group-address [

display igmp-snooping host-tracking vlan

group-address [ chassis-number

display igmp-snooping router-port

vsi-name ] [

display igmp-snooping router-port

vsi-name ] [

display igmp-snooping static-group

source-address ] * [ slot-number ]

display igmp-snooping static-group

chassis-number

slot

chassis

vlan

source

source slot

slot-number ]

chassis-number

vlan

source-address ] [

[ group-address |

vlan-id |

[ group-address |

vlan-id |

slot

slot-number ]

vlan-id ] [

vsi

vsi-name ] [

vsi

vsi-name ] [

vlan

[

vlan

[

slot

slot-number ]

[ group-address |

verbose

[ group-address |

verbose

vlan-id

slot

slot-number ]

vlan-id

chassis

vlan-id |

slot

] [

group

vsi

]

Task

Command

chassis-number

slot

slot-number ]

(In standalone mode.) Display static

all

vlan

vsi

router port information.

display igmp-snooping static-router-port

slot

[

slot-number ]

[

vlan

vlan-id ]

(In IRF mode.) Display static router port information.

Display statistics for the IGMP messages and PIMv2 hello messages learned by IGMP snooping.

(In standalone mode.) D isp lay Lay er 2 multicast fast forw ar ding entr ies.

(In IRF mode.) Display Layer 2 multicast fast forwarding entries.

(In standalone mode.) D isplay inf ormation about Layer 2 IP multicast groups.

(In IRF mode.) Display informa tion abou t Layer 2 IP multicast groups.

(In standalone mode.) Display Layer 2 IP multicast group entries.

(In IRF mode.) Display Layer 2 IP multicast group entries.

(In standalone mode.) D isplay inf ormation about Layer 2 MAC multicast groups.

display igmp-snooping static-router-port

chassis

[

chassis-number

slot

slot-number ]

display igmp-snooping statistics

display l2-multicast fast-forwarding cache

[ source-address | group-address ] * [

slot

slot-number ]

display l2-multicast fast-forwarding cache

[ source-address | group-address ] * [

slot

slot-number ]

display l2-multicast ip

source-address ] * [ slot-number ]

display l2-multicast ip

source-address ] * [ chassis-number

slot

group

[

vlan

vlan-id |

group

[

vlan

vlan-id |

slot-number ]

display l2-multicast ip forwarding source

source-address ] * [

slot-number ]

vlan

display l2-multicast ip forwarding source

[

source-address ] * [

chassis

chassis-number

display l2-multicast mac

vsi-name ] [

slot

slot-number ]

vlan

slot

[ mac-address ] [

chassis

group-address |

vsi

vsi-name ] [

group-address |

vsi

vsi-name ] [

group

[

group

[

vsi

vlan-id |

slot-number ]

vlan

[

vlan-id ]

vlan

[

vlan-id ]

vlan

[

vlan-id ]

chassis-number

source

slot

source

chassis

group-address |

vsi-name ] [

slot

group-address |

vsi-name ]

vlan

vlan-id |

vsi

(In IRF mode.) Display informa tion abou t Layer 2 MAC multicast groups.

(In standalone mode.) Display Layer 2 MAC multicast group entries.

(In IRF mode.) Display Layer 2 MAC multicast group entries.

Display static multicast MAC address entries.

Clear dynamic IGMP snooping group entries.

(In standalone mode.) C lear L ay er 2 multicast fast forwarding entries.

(In IRF mode.) Clear Layer 2 multicast fast forwarding entries.

Clear dynamic router port information.

Clear statistics for IGMP messages and PIMv2 hello messages learned through IGMP snooping.

display l2-multicast mac

vsi-name ] [

chassis

display l2-multicast mac forwarding

vlan-id |

vsi

vsi-name ] [

display l2-multicast mac forwarding

vlan-id | slot-number ]

vsi

vsi-name ] [

display mac-address

multicast

[

] [

vlan

reset igmp-snooping group

[ source-address ] |

[ mac-address ] [

chassis-number

slot

slot-number ]

chassis

[ mac-address [

vlan-id ] [

count

{ group-address

} [

vlan-id |

slot

[ mac-address ] [

chassis-number

vlan

] ]

reset l2-multicast fast-forwarding cache

{ { source-address | group-address } * |

all

reset l2-multicast fast-forwarding cache

{ { source-address | group-address } * | chassis-number

slot

slot-number ]

reset igmp-snooping router-port

vsi-name }

all

{

reset igmp-snooping statisti cs

vlan

vlan-id |

slot-number ]

slot

vlan-id ] |

vsi-name ]

vlan

[

vlan-id ]

slot

} [

slot-number ]

vlan

[

vlan-id ]

chassis

} [

vlan

vlan-id |

vsi

vlan

IGMP snooping configuration examples

•

Source

Router A

IGMP querier

Switch A

Receiver

Host A

Host B

Host C

1.1.1.1/24

GE1/0/4

GE1/0/2

GE1/0/3

GE1/0/1

10.1.1.1/24

GE1/0/2

1.1.1.2/24

VLAN 100

Group policy and simulated joining configuration example (for VLANs)

Network requirements

As shown in Figure 12, Router A runs IGMPv2 and acts as the IGMP querier. Switch A runs IGMPv2 snooping.

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

Host A and Host B receive only the multicast data addressed to multicast group 224.1.1.1.

Multicast data can be forwarded through GigabitEthernet 1/0/3 and GigabitEthernet 1/0/4 of Switch A uninterruptedly, even though Host A and Host B fail to receive the multicast data.

Switch A will drop unk nown m ulticas t data inst ead of flood ing it in VLAN 100.

Figure 12 Network diagram

Configuration procedure

1. Assign an IP address and subnet mask to each interface, as shown in Figure 12. (Details not

shown.)

2. Configure Router A: # Enable IP multicast routing.

<RouterA> system-view [RouterA] multicast routing [RouterA-mrib ] quit

# Enable IGMP on GigabitEthernet 1/0/1.

[RouterA] interface gigabitethernet 1/0/1 [RouterA-GigabitEthernet1/0/1] igmp enable [RouterA-GigabitEthernet1/0/1] quit

# Enable PIM-DM on GigabitEthernet 1/0/2.

[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> sy stem-view [SwitchA] ig mp-snooping [SwitchA-igmp-snooping] quit

# Create VLAN 100, and assign GigabitEthernet 1/0/1 through GigabitEthernet 1/0/4 to the VLAN.

[SwitchA] vlan 100 [SwitchA-vlan100] port gigabiteth ernet 1/0/1 to gigabitethernet 1/0 /4

# Enable IGMP snooping, and enable dropping unknown multicast data for VLAN 100.

[SwitchA-vlan100] igmp-snooping en able [SwitchA-vlan100] igmp-snooping drop-unknown [SwitchA-vlan100] quit

# Configure a multicast group policy so that hosts in VLAN 100 can join only multicast group

224.1.1.1.

[SwitchA] ac l basic 2001 [SwitchA-acl-ipv4-basic-2001] rule permit source 224.1.1.1 0 [SwitchA-acl-ipv4-basic-2001] quit [SwitchA] ig mp-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 member hosts of multicast group 224.1.1.1.

[SwitchA] interface gigabite thernet 1/0/3 [SwitchA-GigabitEthernet1/0/3] igmp-snooping host-join 224.1.1. 1 vlan 100 [SwitchA-GigabitEthernet1/0/3] quit [SwitchA] interface gigabite thernet 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

# Send IGMP reports from Hos t A and Host B to join multicast groups 224.1.1.1 and 224.2.2.2. (Details not shown.)

# Display dynamic IGMP snooping group entries for VLAN 100 on Switch A.

[SwitchA] display igmp-snooping group vl an 100 Total 1 entries.

VLAN 100: Total 1 entries. (0.0.0.0, 224.1.1.1) Host slots (0 in total) : Host ports (2 in total): GE1/0/3 (00:03:23) GE1/0/4 (00:04:10)

The output shows the following information:

Host A and Host B have joined multicast group 224.1.1.1 through the member ports

GigabitEthernet 1/0/4 and Gigab it Ethernet 1/0/3 on Switch A, respectively.

Host A and Host B have failed to join multicast group 224.2.2.2.

Static port configuration example (f or VLANs)

•

Source

1.1.1.1/24

Router A

IGMP querier

GE1/0/1

10.1.1.1/

Switch A

Switch B

Switch C

GE1

/0/1

GE1/0/2

GE1

/0/

1/0/4

Host A

Receiver

Host B

Host C

Receiver

VLAN 100

GE1/0/2

1.1.1.2/24

Network requirements

As shown in Figure 13:

Router A runs IGMPv2 and acts as the IGMP querier. Switch A, Switch B, and Switch C run

IGMPv2 snooping.

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

Configure static ports to meet the following 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. Multicast data flows to the receivers attached to Swi tch C only along the path of Switch A—Switch B—Switch C. When this path is blocked, a minimum of one IGMP query-response cycle must be completed before multicast data flows to the receivers along the path of Switch A—Switch C. In this case, the multicast delivery is interrupted during the process. For more information about the STP, see Layer 2—LAN Switching C onf igur ati on G uide .

Configure GigabitEthernet 1/0/3 on Switch A as a static router port. Then, multicast data can flow to the receivers nearly uninterruptedly along the path of Switch A—Switch C when the path of Switch A—Switch B—Switch C is blocked.

Figure 13 Network diagram

Configuration procedure

1. Assign an IP address and subnet mask to each interface, as shown in Figure 13. (Details not

shown.)

2. Configure Router A: # Enable IP multicast routing.

<RouterA> system-view [RouterA] multicast routing [RouterA-mrib ] quit

# Enable IGMP on GigabitEthernet 1/0/1.

[RouterA] interface gigabitethernet 1/0/1 [RouterA-GigabitEthernet1/0/1] igmp enable

[RouterA-GigabitEthernet1/0/1] quit

# Enable PIM-DM on GigabitEthernet 1/0/2.

[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> sy stem-view [SwitchA] ig mp-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 gigabiteth ernet 1/0/1 to gigabitethernet 1/0 /3

# Enable IGMP snooping for VLAN 100.

[SwitchA-vlan100] igmp-snooping en able [SwitchA-vlan100] quit

# Configure GigabitEthernet 1/0/3 as a static router port.

[SwitchA] interface gigabite thernet 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> sy stem-view [SwitchB] ig mp-snooping [SwitchB-igmp-snooping] quit

# Create VLAN 100, and assign GigabitEthernet 1/0/1 and GigabitEthernet 1/0/2 to the VLAN.

[SwitchB] vlan 100 [SwitchB-vlan100] port gigabiteth ernet 1/0/1 gigabitethernet 1/0/ 2

# Enable IGMP snooping for VLAN 100.

[SwitchB-vlan100] igmp-snooping enable [SwitchB-vlan100] quit

5. Configure Switch C: # Enable IGMP snooping globally.

<SwitchC> sy stem-view [SwitchC] ig mp-snooping [SwitchC-igmp-snooping] quit

# Create VLAN 100, and assign GigabitEthernet 1/0/1 through GigabitEthernet 1/0/5 to the VLAN.

[SwitchC] vlan 100 [SwitchC-vlan100] port gigabiteth ernet 1/0/1 to gigabitethernet 1/0 /5

# Enable IGMP snooping for VLAN 100.

[SwitchC-vlan100] igmp-snooping enable [SwitchC-vlan100] quit

# Configure GigabitEthernet 1/0/3 and Gi gab it Eth ernet 1/ 0/5 as static member ports for multicast group 224.1.1.1.

[SwitchC] in terface gigabitethernet 1/0/3

[SwitchC-Giga bitEthernet1/0 /3] igmp-snooping static-group 224.1.1.1 vlan 100

•

[SwitchC-Giga bitEthernet1/0 /3] quit [SwitchC] in terface gigabitethernet 1/0/5 [SwitchC-Giga bitEthernet1/0 /5] igmp-snooping static-group 224.1.1.1 vlan 100 [SwitchC-Giga bitEthernet1/0 /5] quit

Verifying the configuration

# Display static router port information for VLAN 100 on Switch A.

[SwitchA] display igmp-snooping static-router-port vlan 100 VLAN 100: Router slots (0 in total): Router ports (1 in total): GE1/0/3

The output shows that GigabitEthernet 1/0/3 on Switch A has become a static router port. # Display static IGMP snooping group entries for VLAN 100 on Switch C.

[SwitchC] display igmp-snooping static-group vlan 100 Total 1 entrie s.

VLAN 100: Total 1 entries. (0.0.0.0, 224.1.1.1) Host slots (0 in total) : Host ports (2 in total): GE1/0/3 GE1/0/5

The output shows th at GigabitEth ernet 1/0/3 and GigabitEthernet 1/0/5 on Switc h C have bec ome static member ports of multicast group 224.1.1.1.

IGMP snooping querier configurat ion example (for VLANs)

Network requirements

As shown in Figure 14:

The network is a Layer 2-only network. 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.

All host receivers run IGMPv2, and all switches run IGMPv2 snooping. Switch A (which is close

to the multicast sources) acts as the IGMP snooping querier.

Configure the switches to meet the following requirements:

To prevent the switches from flooding unknown data in the VLAN, enable all the switches to

drop unknown multicast data.

A switch does not mark a port that receives an IGMP query with source IP address 0.0.0.0 as a

dynamic router port. This adversely affects the establishment of Layer 2 forwarding entries and multicast traffic forwarding. To avoid this, configure the source IP address of IGMP queries as a non-zero IP address.

Figure 14 Network diagram

Switch D

Switch A

Querier

Switch B

Switch C

Source 1

192.168.1.10/24

Host D

Receiver

GE1/0/2GE1/0/1

GE1/0/1

GE1/0/2

GE1/0/3 GE1/0/3 GE1/0/1

GE1/0/2

GE1/0/1GE1/0/3

GE1/0/2

Source 2

192.168.1.20/24

Host A Host B

Host C

Receiver Receiver

Receiver

GE1/0/4

VLAN 100

Configuration procedure

1. Configure Switch A:

# Enable IGMP snooping globally.

<SwitchA> sy stem-view [SwitchA] ig mp-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 gigabiteth ernet 1/0/1 to gigabitethernet 1/0/3

# Enable IGMP snooping, and enable dropping unknown multicast data for VLAN 100.

[SwitchA-vlan100] igmp-snooping en able [SwitchA-vlan100] igmp-snooping drop-unknown

# Configure Switch A as the IGMP snooping querier.

[SwitchA-vlan100] igmp-snooping qu erier [SwitchA-vlan100] quit

# In VLAN 100, specify 192.168.1.1 as the source IP address of IGMP general queries.

[SwitchA-vlan100] igmp-snooping ge neral-query source-ip 192.168.1.1

# In VLAN 100, specify 192.168.1.1 as the source IP address of IGMP group-specific queries.

[SwitchA-vlan100] igmp-snooping sp ecial-query source-ip 192.168.1.1 [SwitchA-vlan100] quit

2. Configure Switch B: # Enable IGMP snooping globally.

<SwitchB> sy stem-view [SwitchB] ig mp-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 gigabiteth ernet 1/0/1 to gigabitethernet 1/0/4

# Enable IGMP snooping, and enable dropping unknown multicast data for VLAN 100.

[SwitchB-vlan100] igmp-snooping enable [SwitchB-vlan100] igmp-snooping drop-unknown [SwitchB-vlan100] quit

3. Configure Switch C: # Enable IGMP snooping globally.

<SwitchC> sy stem-view [SwitchC] ig mp-snooping [SwitchC-igmp-snooping] quit

# Create VLAN 100, and assign GigabitEthernet 1/0/1 through GigabitEthernet 1/0/3 to the VLAN.

[SwitchC] vlan 100 [SwitchC-vlan100] port gigabiteth ernet 1/0/1 to gigabitethernet 1/0/3

# Enable IGMP snooping, and enable dropping unknown multicast data for VLAN 100.

[SwitchC-vlan100] igmp-snooping enable [SwitchC-vlan100] igmp-snooping drop-unknown [SwitchC-vlan100] quit

4. Configure Switch D: # Enable IGMP snooping globally.

<SwitchD> sy stem-view [SwitchD] ig mp-snooping [SwitchD-igmp-snooping] quit

# Create VLAN 100, and assign GigabitEthernet 1/0/1 and GigabitEthernet 1/0/2 to the VLAN.

[SwitchD] vlan 100 [SwitchD-vlan100] port gigabiteth ernet 1/0/1 to gigabitethernet 1/0/2

# Enable IGMP snooping, and enable dropping unknown multicast data for VLAN 100.

[SwitchD-vlan100] igmp-snooping enable [SwitchD-vlan100] igmp-snooping drop-unknown [SwitchD-vlan100] quit

Verifying the configuration

# Display statistics fo r IGMP messages and PIMv2 hello messages learned through IGMP snooping on Switch B.

[SwitchB] display igmp-snooping st atistics Received IGM P general queries: 3 Received IGMPv1 reports: 0 Received IGMPv2 reports: 12 Received IGMP leaves: 0 Received IGMPv2 specific queries: 0 Sent IGMPv2 specif ic queries: 0 Received IGMPv3 reports: 0 Received IGMPv3 reports with righ t and wrong records: 0 Received IGMPv3 specific queries: 0 Received IGM Pv3 specific sg quer ies: 0 Sent IGMPv3 specif ic queries: 0 Sent IGMPv3 specific sg queries: 0 Received PIMv2 hello: 0

Received error IG MP messages: 0

•

Source

Router A

IGMP querier

Receiver

Host A

Host B

Host C

1.1.1

.1/

GE1/

0/4

GE1/0/2

GE1/

0/3

GE1/0/1

GE1/

0/1

10.1

.1.

1/24

GE1

/0/

1.1

.1.

2/24

VLAN

100

Switch A

Proxy

The output shows that all switches except Switch A can receive the IGMP general quer ies after Switch A acts as the IGMP snooping querier.

IGMP snooping proxying configuration example (for V LANs)

Network requirements

As shown in Figure 15, Router A runs IGMPv2 and acts as the IGMP querier. Switch A runs IGMPv2 snooping. Configure IGMP snooping proxying so that Switch A can perform the following operations:

Forward IGMP reports and leave messages to Router A. Respond to IGMP queries sent by Router A and forward the queries to downstream hosts.

Figure 15 Network diagram

Configuration procedure

1. Assign an IP address and subnet mask to each interface, as shown in Figure 15. (Details not

shown.)

2. Configure Router A: # Enable IP multicast routing.

<RouterA> sy stem-view [RouterA] mu lticast routing [RouterA-mrib ] quit

# Enable IGMP and PIM-DM on GigabitEthernet 1/0/1.

[RouterA] interface gigabitether net 1/0/1 [RouterA-GigabitEthernet1/0/1] igmp enable [RouterA-Giga bitEthernet1/0 /1] pim dm [RouterA-Giga bitEthernet1/0 /1] quit

# Enable PIM-DM on GigabitEthernet 1/0/2.

[RouterA] interface gigabitether net 1/0/2 [RouterA-GigabitEthernet1/0/2] pim dm [RouterA-GigabitEthernet1/0/2] quit

3. Configure Switch A:

# Enable IGMP snooping globally.

•

<SwitchA> sy stem-view [SwitchA] ig mp-snooping [SwitchA-igmp-snooping] quit

# Create VLAN 100, and assign GigabitEthernet 1/0/1 through GigabitEthernet 1/0/4 to the VLAN.

[SwitchA] vlan 10 0 [SwitchA-vlan 100] port gigabite thernet 1/0/1 to gigabitethernet 1/0/4

# Enable IGMP snooping and IGMP snooping proxying for the VLAN.

[SwitchA-vlan100] igmp-snooping en able [SwitchA-vlan100] igmp-snooping proxy enable [SwitchA-vlan100] quit

Verifying the configuration

# Send IGMP reports from Host A and Host B to join multicast group 224.1.1.1. (Details not shown.) # Display IGMP snooping group membership information on Switch A.

[SwitchA] di splay igmp-snooping group Total 1 entries.

VLAN 100: Total 1 entries. (0.0.0.0, 224. 1.1.1) Host ports (2 in total): GE1/0/3 (00:04:00) GE1/0/4 (00:04:04)

# Display IGMP group membership information on Router A.

[RouterA] di splay igmp group IGMP groups in total: 1 GigabitEthernet1/0/1(10.1.1.1): IGMP groups reported in total: 1 Group address Last reporter Uptime Expire s

224.1.1.1 0.0.0.0 00:00:31 00:02:03

# Send an IGMP leave message from Host A to leave multicast group 224.1.1.1. (Details not shown.) # Display IGMP snooping group membership information on Switch A.

[SwitchA] di splay igmp-snooping group Total 1 entrie s.

VLAN 100: Total 1 entries. (0.0.0.0, 224. 1.1.1) Host ports (1 in total): GE1/0/3 ( 00:01:23 )

IGMP snooping configuration exam ple (for VXLANs)

Network requirements

As shown in Figure 16:

VXLAN 10 provides Layer 2 connectivity for VM 1, VM 2, and VM 3 across the network sites. VXLAN 10 uses the unicast mode for flood traffic.

Configure IGMP snooping on the switches to implement Layer 2 multicast forwarding and reduce the

Device

Interface

IP address

Device

Interface

IP address

Switch A

Vlan-int11

11.1.1.1/24

Switch C

Vlan-int13

13.1.1.3/24

Switch A

Loop0

1.1.1.1/32

Switch C

3.3.3.3/32

Switch B

Vlan-int12

12.1.1.2/24

Switch D

11.1.1.4/24

Switch D

Vlan-int13

13.1.1.4/24

Switch A

Switch C

Transport network

Switch

GE1

1 GE

Switch B

Server

VM 2

Server 1

Server

Loop

0 Loop

Loop

VLAN

VLAN 2

VLAN

Vlan

int11

Vlan-

int

Vlan

int

Vlan-

int11

Vlan

int

Vlan

-int

burden of replicating known multicast traffic for VTEPs in VXLAN 10.

Figure 16 Network diagram

Table 8 Interface and IP address assignment

Switch B Loop0 2.2.2.2/32 Switch D

1. Assign an IP address and subnet mask to each interface on the transport network, as shown i n

Table 8. (Details not shown.)

2. Configure OSPF on all the switches in the transport network. (Details not shown.)

3. Configure Switch A:

# Enable L2VPN.

<SwitchA> sy stem-view [SwitchA] l2 vpn enable

# Create a VSI named vpna, and create VXLAN 10.

[SwitchA] vs i vpna [SwitchA-vsi-vpna] vxlan 10 [SwitchA-vsi-vpna-vxlan-10] quit [SwitchA-vsi-vpna] quit

# Enable IGMP snooping globally.

[SwitchA] ig mp-snooping [SwitchA -igmp-snooping] quit

# Enable IGMP snooping and dropping unknown multicast data packets for VSI vpna.

[SwitchA] vs i vpna [SwitchA-vsi-vpna] igmp-snooping enab le [SwitchA-vsi-vpna] igmp-snooping drop-unknown [SwitchA-vsi-vpna] quit

Loop0 Vlan-int11 Vlan-int12

12.1.1.4/24

# Assign an IP address to Loopback 0. This IP address will be used as the source address of the VXLAN tunnels to Switch B and Switch C.

[SwitchA] in terface loopback 0 [SwitchA-Loop back0] ip address 1. 1.1.1 255.255.255.255 [SwitchA-Loopback0] quit

# Create a VXLAN tunnel to Switch B.

 The tunnel interface name is Tunnel 1.  The source address and destination address of the tunnel interface are 1.1.1.1 and 2.2.2.2,

respectively.

[SwitchA] interface tunnel 1 mode vxlan [SwitchA-Tunnel1] source 1.1.1.1 [SwitchA-Tunnel1] destination 2.2.2.2 [SwitchA-Tunnel1] quit

# Create a VXLAN tunnel to Switch C.

 The tunnel interface name is Tunnel 2.  The source address and destination address of the tunnel interface are 1.1.1.1 and 3.3.3.3,

respectively.

[SwitchA] interface tunnel 2 mode vxlan [SwitchA-Tunnel2] source 1.1.1.1 [SwitchA-Tunnel2] destination 3.3.3.3 [SwitchA-Tunnel2] quit

# Assign Tunnel 1 and Tunnel 2 to VXLAN 10.

[SwitchA] vs i vpna [SwitchA-vsi-vpna] vxlan 10 [SwitchA-vsi-vpna-vxlan-10] tunnel 1 [SwitchA-vsi-vpna-vxlan-10] tunnel 2 [SwitchA-vsi-vpna-vxlan-10] quit [SwitchA-vsi-vpna] quit

# Configure GigabitEthernet 1/0/1 as a trunk port and assign it to VLAN 2.

[SwitchA] in terface gigabitethernet 1/0/1 [SwitchA-GigabitEthernet1/0/1] port link-t ype trunk [SwitchA-GigabitEthernet1/0/1] port trunk permit vlan 2

# On GigabitEthernet 1/0/1, create Ethernet service instance 1000 to match VLAN 2.

[SwitchA-GigabitEthernet1/0/1] service-instance 1000 [SwitchA-GigabitEthernet1/0/1-srv1000] encapsulation s-vid 2

# Map Ethernet service instance 1000 to VSI vpna.

[SwitchA-GigabitEthernet1/0/1-srv1000] xconnect vsi vpna [SwitchA-GigabitEthernet 1/0/1-s rv1000] quit [SwitchA-GigabitEthernet 1/0/1] quit

4. Configure Switch B: # Enable L2VPN.

<SwitchB> sy stem-view [SwitchB] l2 vpn enable

# Create a VSI named vpna, and create VXLAN 10.

[SwitchB] vs i vpna [SwitchB-vsi-vpna] vxlan 10 [SwitchB-vsi-vpna-vxlan-10] quit [SwitchB-vsi-vpna] quit

# Enable IGMP snooping globally.

[SwitchB] ig mp-snooping [SwitchB -igmp-snooping] quit

# Enable IGMP snooping and dropping unknown multicast data packets for VSI vpna.

[SwitchB] vs i vpna [SwitchB-vsi-vpna] igmp-snooping enab le [SwitchB-vsi-vpna] igmp-snooping drop-unknown [SwitchB-vsi-vpna] quit

# Assign an IP address to Loopback 0. This IP address will be used as the source address of the VXLAN tunnels to Switch A and Switch C.

[SwitchB] in terface loopback 0 [SwitchB-Loop back0] ip address 2. 2.2.2 255.255.255.255 [SwitchB-Loopback0] quit

# Create a VXLAN tunnel to Switch A.

 The tunnel interface name is Tunnel 2.  The source address and destination address of the tunnel interface are 2.2.2.2 and 1.1.1.1,

respectively.

[SwitchB] interface tunnel 2 mode vxlan [SwitchB-Tunnel2] source 2.2.2.2 [SwitchB-Tunnel2] destination 1.1.1.1 [SwitchB-Tunnel2] quit

# Create a VXLAN tunnel to Switch C.

 The tunnel interface name is Tunnel 3.  The source address and destination address of the tunnel interface are 2.2.2.2 and 3.3.3.3,

respectively.

[SwitchB] interface tunnel 3 mode vxlan [SwitchB-Tunnel3] source 2.2.2.2 [SwitchB-Tunnel3] destination 3.3.3.3 [SwitchB-Tunnel3] quit

# Assign Tunnel 2 and Tunnel 3 to VXLAN 10.

[SwitchB] vs i vpna [SwitchB-vsi-vpna] vxlan 10 [SwitchB-vsi-vpna-vxlan-10] tunnel 2 [SwitchB-vsi-vpna-vxlan-10] tunnel 3 [SwitchB-vsi-vpna-vxlan-10] quit [SwitchB-vsi-vpna] quit

# Configure GigabitEthernet 1/0/1 as a trunk port and assign it to VLAN 2.

[SwitchB] in terface gigabitethernet 1/0/1 [SwitchB-GigabitEthernet1/0/1] port link-t ype trunk [SwitchB-GigabitEthernet1/0/1] port trunk permit vlan 2

# On GigabitEthernet 1/0/1, create Ethernet service instance 1000 to match VLAN 2.

[SwitchB-GigabitEthernet1/0/1] service-instance 1000 [SwitchB-GigabitEthernet1/0/1-srv1000] encapsulation s-vid 2

# Map Ethernet service instance 1000 to VSI vpna.

[SwitchB-GigabitEthernet1/0/1-srv1000] xconnect vsi vpna [SwitchB-GigabitEthernet1/0/1-srv1000] quit [SwitchB-GigabitEthernet1/0/1] quit

5. Configure Switch C:

# Enable L2VPN.

<SwitchC> sy stem-view [SwitchC] l2vpn enable

# Create a VSI named vpna, and create VXLAN 10.

[SwitchC] vs i vpna [SwitchC-vsi-vpna] vxlan 10 [SwitchC-vsi-vpna-vxlan-10] quit [SwitchC-vsi-vpna] quit

# Enable IGMP snooping globally.

[SwitchB] ig mp-snooping [SwitchB -igmp-snooping] quit

# Enable IGMP snooping for VSI vpna.

[SwitchC] vs i vpna [SwitchC-vsi-vpna] igmp-snooping enab le

# Enable dropping unknown multicast data packets for VSI vpna.

[SwitchC-vsi-vpna] igmp-snooping drop-unknown

# Specify 3.3.3.3 as the source IP address of IGMP general queries in V SI vpna.

[SwitchC-vsi-vpna] igmp-snooping gene ral-query source -ip 3.3.3.3

# Enable the IGMP snooping querier.

[SwitchC-vsi-vpna] igmp-snooping quer ier [SwitchC-vsi-vpna] quit

# Assign an IP address to Loopback 0. This address will be used as the source address of the VXLAN tunnels to Switch A and Switch B.

[SwitchC] in terface loopback 0 [SwitchC-Loop back0] ip address 3. 3.3.3 255.255.255.255 [SwitchC-Loopback0] quit

# Create a VXLAN tunnel to Switch A.

 The tunnel interface name is Tunnel 1.  The source address and destination address of the tunnel interface are 3.3.3.3 and 1.1.1.1,

respectively.

[SwitchC] interface tunnel 1 mode vxlan [SwitchC-Tunnel1] source 3.3.3.3 [SwitchC-Tunnel1] destination 1.1.1.1 [SwitchC-Tunnel1] quit

# Create a VXLAN tunnel to Switch B.

 The tunnel interface name is Tunnel 3.  The source address and destination address of the tunnel interface are 3.3.3.3 and 2.2.2.2,

respectively.

[SwitchC] interface tunnel 3 mode vxlan [SwitchC-Tunnel3] source 3.3.3.3 [SwitchC-Tunnel3] destination 2. 2.2.2 [SwitchC-Tunnel3] quit

# Assign Tunnel 1 and Tunnel 3 to VSI vpna.

[SwitchC] vs i vpna [SwitchC-vsi-vpna] vxlan 10 [SwitchC-vsi-vpna-vxlan-10] tunnel 1 [SwitchC-vsi-vpna-vxlan-10] tunnel 3 [SwitchC-vsi-vpna-vxlan-10] quit

[SwitchC-vsi-vpna] quit

# Configure GigabitEthernet 1/0/1 as a trunk port and assign it to VLAN 2.

[SwitchC] in terface gigabitethernet 1/0/1 [SwitchC-GigabitEthernet1/0/1] port link-t ype trunk [SwitchC-GigabitEthernet1/0/ 1] port trunk permit v lan 2

# On GigabitEthernet 1/0/1, create Ethernet service instance 1000 to match VLAN 2.

[SwitchC-GigabitEthernet1/0/1] service-instance 1000 [SwitchC-GigabitEthernet1/0/1-srv1000] encapsulation s-vid 2

# Map Ethernet service instance 1000 to VSI vpna.

[SwitchC-GigabitEthernet1/0/1-srv1000] xconnect vsi vpna [SwitchC-GigabitEthernet1/0/1-srv1000] quit [SwitchC-GigabitEthernet1/0/1] quit

Verifying the configuration

# Display dynamic router port information for VSI vpna on Switch A.

[SwitchA] di splay igmp-snooping router-port vsi vpna VSI vpna: Router slots (0 in total): Router ports (1 in total): NPW (VXLAN ID 10 Lin k ID 0X5000001) (00:04:17)

# Display dynamic router port information for VSI vpna on Switch B.

[SwitchB] di splay igmp-snooping router-port vsi vpna VSI vpna: Router slots (0 in total): Router ports (1 in total): NPW (VXLAN ID 10 Link ID 0X5000001) (00:04:07)

Troubleshooting IGMP snooping

Layer 2 multicast forwarding cannot function

Symptom

Layer 2 multicast forwarding cannot function on the Layer 2 device.

Solution

To resolve the problem:

1. Use the display igmp-snooping command to display IGMP snooping status.

2. If IGMP snooping is not enabled, use the igmp-snooping command in system view to enabl e

IGMP snooping globally. Then, use the igmp-snooping enable command in VLAN view or VSI view to enable IGMP snooping for the VLAN or VSI.

3. If IGMP snooping is enabled globally but not enabled for the VLAN, use the igmp-snooping enable command in VLAN view or VSI view to enable IGMP snooping for the VLAN or VSI.

4. If the problem persists, contact Hewlett Packard Enterprise Support.

Multicast group poli cy does not work

Symptom

Hosts can receive m ulticast dat a for multicast grou ps that ar e not p erm itted by the m ulticast group policy.

Solution

To resolve the problem:

1. Use the display acl command to verify that the configured ACL meets the multicast group policy requirements.

2. Use the display this command in IGMP-snooping view or in a corresponding interface view to verify that the correct multicast group policy has been applied. If the applied policy is not correct, use the group-policy or igmp-snooping group-policy command to apply the correct multicast group policy.

3. Use the display igmp-snooping command to verify that dropping unknown multicast data is enabled. If it is not, use the drop-unknown or igmp-snooping drop-unknown command to enable dropping unknown multicast data.

4. If the problem persists, contact Hewlett Packard Enterprise Support.

•

Multicast packet transmission

when only

IGMP snooping runs

Multicast packet transmission when

IGMP snooping and PIM snooping both run

Source 1

Source 2

Receiver 1 Receiver 2

Multicast packets (S1, G1) Join message (S1, G1)

Layer 2 switch

Source 1

Source 2

Receiver 1 Receiver 2

Layer 2 switch

Multicast packets (S2, G2) Join message (S2, G2)

PIM

router 3

PIM

router 1

PIM

router 2

PIM

router 4

PIM

router 3

PIM

router 1

PIM

router 2

PIM

router 4

Configuring PIM snooping

Overview

PIM snooping runs on Layer 2 devices. It works with IGMP snooping to analyze received PIM messages, and adds the ports that are interested in specific multicast data to a PIM snooping routing entry . In this way, the multicast data can be forwarded to only the ports that are interested in the data.

Figure 17 Multicast packet transmission without or with PIM snooping

As shown in Figure 17, Sourc e 1 sends multicast dat a to multicast gr oup 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 routers are in the same VLAN.

When the Layer 2 switch runs only IGMP snooping, it performs the following actions:

a. Maintains the router ports according to the received PIM hello messages that PIM routers

b. Floods all other types of received PIM messages except PIM hello messages in the VLAN

c. Forwards all multicast data to all router ports in the VLAN or VSI.

send.

or VSI.

•

IMPORTANT:

Do not configure PIM snooping in secondary VLANs because PIM snooping does

on secondary VLANs. Configuration Guide.

Step

Command

Remarks

vsi

interface or AC interface that acts as

Each PIM router in the VLAN or VSI, 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 performs the following

actions: d. Examines whether a PIM router is interested in the multicast data addressed to a multicast

group according to the received PIM messages that the router send.

e. Adds only the ports that connect to the router and are interested in the data to a PIM

snooping routing entry.

f. Forwards PIM messages and multicast data to only the routers that are interested in the

data, which saves network bandwidth. For more information about IGMP snooping and the router port, see "Configuring IGMP snooping." PIM snooping can run in PIM-SM and PIM-SSM networks. Do not configure PIM snooping in

PIM-DM or BIDIR-PIM networks. For more information about PIM, see "Configuring PIM."

Configuring PIM snooping

not take effect

For more information about secondary VLANs, see Layer 2—LAN Switching

T o configure P IM snooping for a VLAN or VSI, you must enable IGMP snooping globally on the Layer 2 device, and then enable IGMP snooping and PIM snooping for the VLAN or VSI.

After you enable PIM snooping for a VLAN or VSI, PIM snooping works only on the member interfaces of the VLAN or VSI.

To configure PIM snooping:

1. Enter system view.

2. Enable IGMP snooping

globally and enter IGMP-snooping view.

3. Return to system view.

4. Enter VLAN view or VSI

view.

5. Enable IGMP snooping for the VLAN or VSI.

6. Enable PIM snooping for the VLAN or VSI.

7. (Optional.) Set the aging time for global neighbor ports on the new active MPU after an active/standby switchover.

system-view

igmp-snooping

quit

• Enter VLAN view:

vlan vlan-id

• Enter VSI view: vsi-name

igmp-snooping enable

pim-snooping enable

pim-snooping graceful-restart neighbor-aging-time

seconds

N/A By default, IGMP snooping is

disabled. N/A

N/A

By default, IGMP snooping is disabled in a VLAN.

By default, PIM snooping is disabled in a VLAN or VSI.

The default setting is 105 seconds. A global neighbor port is a Layer 2

aggregate interface or AC interface that acts as a neighbor port.

8. (Optional.) Set the aging time for global downstream ports and global router po rt s on the new active MPU after

pim-snooping graceful-restart join-aging-time

seconds

The default setting is 210 seconds. A global downstream por t or a global

router port is a Layer 2 aggregate

Step

Command

Remarks

an active/standby

a downstream port or router port.

Task

Command

•

switchover.

Displaying and maintaining PIM snooping

Execute display commands in any view and reset commands in user view.

(In standalone mode.) Display PIM snooping neighbor information.

(In IRF mode.) Display PIM snooping neighbor information.

(In standalone mode.) Display PIM snooping router port information.

(In IRF mode.) Display PIM snooping router port information.

(In standalone mode.) Display PIM snooping routing entries.

(In IRF mode.) Display PIM snooping ro uting en trie s.

Display statistics for the PIM messages learned through PIM snooping.

Clear statistics for the PIM messages learned through PIM snooping.

display pim-snooping neighbor

vsi-name ] [

display pim-snooping neighbor

vsi-name ] [ slot-number ] [

display pim-snooping router-port vsi

vsi-name ] [

display pim-snooping router-port vsi

vsi-name ] [

slot-number ]

display pim-snooping routing-table vsi

vsi-name ] [

display pim-snooping routing-table vsi

vsi-name ] [

slot-number ] [

display pim-snooping statistics

reset pim-snooping statistic s

slot

slot-number ] [

chassis

chassis-number

verbose ]

slot

slot-number ]

chassis

slot

slot-number ] [

chassis

verbose ]

PIM snooping configuration example

vlan

[

verbose

vlan

[

slot

vlan

[

vlan

[

chassis-number

vlan

[

verbose

vlan

[

chassis-number

vlan-id |

]

vlan-id |

slot

vlan-id |

]

vlan-id |

slot

vsi

Network requirements

As shown in Figure 18:

OSPF runs on the network. Source 1 and Source 2 send multicast data to multicast groups 224. 1.1. 1 and 225.1.1.1,

respectively.

Receiver 1 and Receiver 2 belong to multicast groups 224.1.1.1 and 225.1.1.1, respectively. Router C and Router D run IGMP on GigabitEthernet 1/0/1. Router A, Router B, Router C, and

Router D run PIM-SM.

GigabitEthernet 1/0/2 on Router A acts as a C-BSR and a C-RP.

Configure IGMP snooping and PIM snooping on S witch A. Then, Switch A forwards PIM prot ocol packets and multicast data packets only to the routers that are connected to receivers.

Source 1

Receiver 1

Receiver 2

Source 2

Switch A

Router A

Router B Router D

Router C

GE1/0/1

1.1.1.1/24

1.1.1.100/24

2.1.1.100/24

GE1/0/2

10.1.1.1/24

GE1/0/1

2.1.1.1/24

GE1/0/1

3.1.1.1/24

GE1/0/1

4.1.1.1/24

3.1.1.100/24

4.1.1.100/24

GE1/0/2

10.1.1.2/24

GE1/0/2

10.1.1.3/24

GE1/0/2

10.1.1.4/24

GE1/0/1

GE1/0/2

GE1/0/3

GE1/0/4

Figure 18 Network diagram

Configuration procedure

1. Assign an IP address and subnet mask to each interface, as shown in Figure 18. (Details not shown.)

2. Configure OSPF on the routers. (Details not shown.)

3. Configure Router A:

# Enable IP multicast routing.

<RouterA> system-view [RouterA] multicast routing [RouterA-mrib] quit

# Enable PIM-SM on each interface.

[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

# Configure GigabitEthernet 1/0/2 as a C-BSR and a C-RP.

[RouterA] pim [RouterA-pim ] c-bsr 10.1.1.1 [RouterA-pim ] c-rp 10.1.1.1 [RouterA-pim ] quit

4. Configure Router B: # Enable IP multicast routing.

<RouterB> system-view [RouterB] multicast routing [RouterB-mrib] qu it

# Enable PIM-SM on each interface.

[RouterB] interface gigabitethernet 1/0/1 [RouterB-GigabitEthernet1/0/1] pim sm [RouterB-GigabitEthernet1/0/1] quit

[RouterB] interface gigabi tethernet 1/0/2 [RouterB-GigabitEthernet1/0/2] pim sm [RouterB-GigabitEthernet1/0/2] quit

5. Configure Router C: # Enable IP multicast routing.

<RouterC> system-view [RouterC] multicast routing [RouterC-mrib] qu it

# Enable IGMP on GigabitEthernet 1/0/1.

[RouterC] interface gigabitethernet 1/0/1 [RouterC-GigabitEthernet1/0/1] igmp enable [RouterC-GigabitEthernet1/0/1] quit

# Enable PIM-SM on GigabitEthernet 1/0/2.

[RouterC] interface gigabitethernet 1/0/2 [RouterC-GigabitEthernet1/0/2] pim sm [RouterC-GigabitEthernet1/0/2] quit

6. Configure Router D: # Enable IP multicast routing.

<RouterD> system-view [RouterD] multicast routing [RouterD-mrib] qu it

# Enable IGMP on GigabitEthernet 1/0/1.

[RouterD] interface gigabitethernet 1/0/1 [RouterD-GigabitEthernet1/0/1] igmp enab le [RouterD-GigabitEthernet1/0/1] quit

# Enable PIM-SM on GigabitEthernet 1/0/2.

[RouterD] interface gigabitethernet 1/0/2 [RouterD-GigabitEthernet1/0/2] pim sm [RouterD-GigabitEthernet1/0/2] quit

7. Configure Switch A: # Enable IGMP snooping globally.

<SwitchA> sy stem-view [SwitchA] ig mp-snooping [SwitchA-igmp-snooping] quit

# Create VLAN 100, and assign GigabitEthernet 1/0/1 through GigabitEthernet 1/0/4 to the VLAN.

[SwitchA] vlan 10 0 [SwitchA-vlan 100] port gigabite thernet 1/0/1 to gigabitethernet 1/0/4

# Enable IGMP snooping and PIM snooping for VLAN 100.

[SwitchA-vlan100] igmp-snooping en able [SwitchA-vlan100] pim-snooping enable [SwitchA-vlan100] quit

Verifying the c onfiguration

# On Switch A, display PIM snooping neighbor information for VLAN 100.

[SwitchA] di splay pim-snooping neighbor vlan 100

•

Total 4 neighbors.

VLAN 100: Total 4 neighbors.

10.1.1.1

Slots (0 in total): Ports (1 in total): GE1/0/1 (00:32:43)

10.1.1.2

Slots (0 in total): Ports (1 in total): GE1/0/2 (00:32:43)

10.1.1.3

Slots (0 in total): Ports (1 in total): GE1/0/3 (00:32:43)

10.1.1.4

Slots (0 in total): Ports (1 in total): GE1/0/4 (00:32:43)

The output shows that Router A, Router B, Router C, and Router D are PIM snooping neighbors. # On Switch A, display PIM snooping routing entries for VLAN 100.

[SwitchA] di splay pim-snooping routing-table vlan 100 Total 2 entries. FSM Flag: NI-no in fo, J-join, PP-prune pending

VLAN 100: Total 2 entries. (*, 224.1.1.1) Upstream neighbor: 10.1.1 .1 Upstream Slots (0 in total): Upstrea m Ports (1 in total): GE1/0/1 Downstream Slots (0 in total): Downstream Ports (1 in tota l): GE1/0/3 Expires: 00:03:01 , FSM: J (*, 225.1.1.1) Upstream neighbor: 10.1.1 .2 Upstream Slots (0 in total): Upstrea m Ports (1 in total): GE1/0/2 Downstream Slots (0 in total): Downstr eam Ports (1 in total): GE1/0/4 Exp ires: 00:03:11, FSM: J

The output shows the following information:

Switch A will forward the multicast data intended for multicast group 224.1.1.1 only to Router C. Switch A will forward the multicast data intended for multicast group 225.1.1.1 only to Router D.

Troubleshooting PIM snooping

PIM snooping does n ot work on a Layer 2 dev i c e

Symptom

PIM snooping does not work on a Layer 2 device.

Solution

To resolve the problem:

1. Use the display current-configuration command to display information about IGMP snooping and PIM snooping.

2. If IGMP snooping is not enabled, enable IGMP snooping globally, and then enable IGMP snooping and PIM snooping for the VLAN.

3. If PIM snooping is not enabled, enable PIM snooping for the VLAN.

4. If the problem persists, contact Hewlett Packard Enterprise Support.

•

Source

Receiver

Host A

Multicast packets

VLAN 2

VLAN 3

VLAN 4

VLAN 2 VLAN 3 VLAN 4

Switch B

Receiver

Host B

Receiver

Host C

Switch A

IGMP querier

Configuring multicast VLANs

Overview

As shown in Figure 19, Host A, Host B, and Host C are in three different VL ANs and the same multicast group. When S witch A (La yer 3 device) receives multicast data f or that group, it sends three copies of the multicast data to Switch B (Layer 2 device). This occupies a large amount of bandwidth and increases the burden on the Layer 3 device.

Figure 19 Multicast transmission without the m u lticast VLAN feature

After a multicast VLAN is configured on Switch B, Switch A sends only one copy of the multicast data to the multicast VL AN on Switc h B. T his method saves net work band width an d les s ens the bur den on the Layer 3 device.

Multicast VLANs include sub-VLAN-based multicast VLANs and port-based multicast VLANs.

Sub-VLAN-based multicast VLAN

As shown in Figure 20:

Host A, Host B, and Host C are in VLAN 2 through VLAN 4, respectively. On Switch B, 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 and its sub-VLANs.

•

Source

Switch A

IGMP querier

VLAN 2

VLAN 3

VLAN 4

Switch B

Receiver

Host A

Receiver

Host B

Receiver

Host C

Multicast packets

VLAN 2 VLAN 3 VLAN 4

VLAN 10 (Multicast VLAN)

Source

VLAN 2

VLAN 3

VLAN 4

GE1/0/1

GE1/0/2

GE1/0/3

GE1/0/4

Switch B

Multicast packets

Receiver

Host A

Receiver

Host B

Receiver

Host C

Switch A

IGMP querier

VLAN 10 (Multicast VLAN)

Figure 20 Sub-VLAN-based multicast VLAN

IGMP snooping manages router ports in the m ulticas t VLAN an d member ports in each sub-VLAN. When Switch A receiv es multicast data from the m ulticast source, it sends only o ne copy of the multicast data to the m ulticast VLAN on Switch B. Then, Switch B sends a separate cop y to each sub-VLAN in the multicast VLAN.

Port-based multicast VLAN

As shown in Figure 21:

Host A, Host B, and Host C are in VLAN 2 through VLAN 4, respectively. On Switch B, VLAN 10 is a multicast VLAN. All the user ports are hybrid ports and are assigned

to VLAN 10.

IGMP snooping is enabled for the multicast VLAN and VL AN 2 through VL AN 4.

Figure 21 Port-based multicast VLAN

IGMP snooping manages the router ports and member ports in the multicast VLAN. When Switch A receives multicast data from the multicast source, it sends only one copy of the multicast data to the multicast VL AN on Switch B. Switch B sends a separate copy to each user port in the multicast VLAN.

Tasks at a glance

•

Multicast VLAN configuration task list

(Required.) Perform one of the following tasks:

• Configuring a sub-VLAN-based multicast VLAN

• Configuring a port-based multicast VLAN:

 Configuring user port attributes  Assigning user ports to a multicast VLAN

(Optional.) Setting the maximum number of multicast VLAN forwarding entries

When you configure the multicast VLANs, follow these guidelines:

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 takes effect.

Do not configure a multicast VLAN on a device that is enabled with IP multicast routing.

Otherwise, the system displays errors.

Do not enable IP multicast routing on a device that is configured with multicast VLANs.

Otherwise, multicast forwarding exceptions occur.

Do not configure a VLAN as a multicast VLAN or a multicast sub-VLAN if the VLAN interface is

enabled with PIM or IGMP. Otherwise, the system displays errors.

Do not enable PIM or IGMP on a VLAN interface if the VLAN interface belongs to a multicast

VLAN or a multicast sub-VLAN. Otherwise, multicast forwarding exceptions occur.

The multicast VLAN feature does not take effect on secondary VLANs. As a best practice, do

not configure the multicast VLAN feature for secondary VLANs. For more information about

—

secondary VLANs, see Layer 2

LAN Switching Configuration Guide.

Configuring a sub-VLAN-based multicast VLAN

To configure a sub-VLAN-based multicast VLAN, configure a VLAN as a multicast VLAN, and assign the VLANs that contain multicast receivers to the multicast VLAN as sub-VLANs.

Configuration prerequisites

Before you configure a sub-VLAN-based multicast VLAN, complete the following tasks:

Create VLANs as required. Enable IGMP snooping for the VLAN to be configured as the multicast VLAN, and for the

VLANs to be configured as s ub-VLANs.

Configuration restrictions and guidelines

When you configure a sub-VLAN-based multicast VLAN, follow these restrictions and guidelines:

The VLAN to be configured as the multicast VLAN must exist. The VLANs to be configured as sub-VLANs of the multicast VLAN must exist and cannot be

multicast VLANs or sub-VLANs of any other multicast VLAN.

You can configure a maximum of five multicast VLANs.

Step

Command

Remarks

•

Step

Command

Remarks

Configuration procedure

To configure a sub-VLAN-based multicast VLAN:

1. Enter system view.

2. Configure a VLAN as a

multicast VLAN and enter its view.

3. Assign the specified VLANs to the multicast VLAN as sub-VLANs.

system-view

multicast-vlan

subvlan

vlan-list

vlan-id

N/A By default, a VLAN is not a

multicast VLAN.

By default, a multicast V LAN does not have any sub-VLANs.

Configuring a port-based multicast VLAN

Y ou can assign only Layer 2 Ethernet interfaces or Layer 2 aggregate interfaces to a multicast VLAN.

Configuration prerequisites

Before you configure a port-based multicast VLAN, complete the following tasks:

Create VLANs as required. Enable IGMP snooping for the VLAN to be configur ed as the m ult ic as t V L AN . Enable IGMP snooping for all the VLANs that contain the multicast receivers.

Configuring user por t attributes

1. Enter system view.

2. Enter interface view.

3. Configure the link type of the

user port as hybrid.

4. Specify the PVID of the current user port as the VLAN to which the user port belongs.

5. Configure the current user port to permit multicast VLAN and to untag the packets.

system-view interface

interface-number

port link-type hybrid

port hybrid pvid vlan

port hybrid vlan untagged

interface-type

vlan-id-list

vlan-id

N/A

The default setting is For more information about this

command, see Layer 2—LAN Switching Command Reference.

By default, the PVID for a hybrid port is VLAN 1.

For more information about this command, see Layer 2—LAN Switching Command Reference.

By default, a hybrid port permits only VLAN 1.

For more information about this command, see Layer 2—LAN Switching Command Reference.

access

•

Step

Command

Remarks

Step

Command

Remarks

Step

Command

Remarks

Assigning user ports to a multicast VLAN

You can assign user ports to a m ulticast VLAN in multicast VLAN view or assign a user port to a multicast VLAN in interface view. These configurations have the same priority.

Configuration restrictions and guidelines

When you assign user ports to a multicast VLAN, follow these restrictions and guidelines:

The VLAN to be configured as a multicast VLAN must exist. A port can belong to only one multicast VLAN.

Configuration procedure

To assign user ports to a multicast VLAN in multicast VLAN view:

1. Enter system view.

2. Configure a VLAN as a

multicast VLAN and enter its view.

3. Assign ports to the multicast VLAN.

To assign a user port to a multicast VLAN in interface view:

1. Enter system view.

2. Configure a VLAN as a

multicast VLAN and enter its view.

3. Return to system view.

4. Enter interface view.

5. Assign the current p ort to the

multicast VLAN.

system-view

multicast-vlan

port

interface-list

system-view

multicast-vlan

quit interface

interface-number

port multicast-vlan

vlan-id

interface-type

vlan-id

N/A By default, a VLAN is not a

multicast VLAN.

By default, a multicast V LAN d oes not have any user ports.

N/A By default, a VLAN is not a

multicast VLAN. N/A

N/A

By default, a user port does not belong to any multicast VLAN.

Setting the maximum number of multicast VLAN forwarding entries

You can set the max imum number of multicast VLAN forwarding entries on the device. W hen the upper limit is reached, t he device does not create multicas t VLAN forwarding entries until some entries age out or are manually removed.

If the total number of the entries exceeds the upper limit value that you are setting, the system does not automatically remove existing entries or create new entries. In this case, remove excess entries manually.

To set the maximum number of multicast VLAN forwarding entries:

1. Enter system view.

system-view

N/A

Step

Command

Remarks

Task

Command

•

2. Set the maximum number of multicast VLAN forwarding entries.

multicast-vlan entry-limit

limit

By default, the maximum number of multicast VLAN forwarding entries is 16384.

Displaying and maintaining multicast VLANs

Execute display commands in any view and reset commands in user view.

Display information about multicast VLANs.

(In standalone mode.) Display information about multicast groups in multicast VLANs.

(In IRF mode.) Display information about multicast groups in multicast VLANs.

(In standalone mode.) Display information about multicast VLAN forwarding entries.

(In IRF mode.) Display information about multicast VLAN forwarding entries.

display multicast-vlan

display multicast-vlan group slot

slot-number |

display multicast-vlan group chassis

display multicast-vlan forwarding-table

{ mask-length | mask } ] | source-address [ mask } ] |

display multicast-vlan forwarding-table

{ mask-length | mask } ] | source-address [ mask } ] | vlan-id |

chassis-number

slot

slot-number |

chassis

vlan

vlan-id ] *

[ vlan-id ]

[ source-address | group-address |

verbose

chassis-number

slot

subvlan

vlan

[ source-address | group-address |

slot-number |

vlan-id ] *

vlan-id |

slot

slot-number |

verbose

[ group-address [

mask

vlan

[ group-address [

mask

vlan

{ mask-length |

vlan-id ] *

{ mask-length |

subvlan

vlan-id ] *

mask

Clear multicast groups in multicast VLANs.

reset multicast-vlan group

mask } ] | group-address [ vlan-id ] *

[ source-address [

mask

{ mask-length | mask } ] |

mask

{ mask-length |

vlan

Multicast VLAN configuration examples

Sub-VLAN-based mul ticast VLAN configuration example

Network requirements

As shown in Figure 22:

Layer 3 device Switch A runs IGMPv2 and acts as the IGMP querier. Layer 2 device Switch B

runs IGMPv2 snooping.

The multicast source sends multicast data to multicast group 224.1.1.1. Receivers Host A, Host

B, and Host C belong to VLAN 2, VLAN 3, and VLAN 4, respectively.

Configure a sub-VLAN-based multicast VLAN on Switch B to meet the following requirements:

Switch A sends the multicast data to Switch B through the multicast VLAN. Switch B forwards the multicast data to the receivers in different user VLANs.

Source

Receiver

Host A

VLAN

GE1

/0/3

GE1

Switch B

IGMP querier

Switch A

Receiver

Host B

VLAN 3

Receiver

Host C

VLAN

GE1

GE1/0

Vlan

int10

110.

/24

Vlan

int20

1.2/24

Figure 22 Network diagram

Configuration procedure

1. Configure Switch A:

# Enable IP multicast routing.

<SwitchA> sy stem-view [SwitchA] mu lticast routing [SwitchA-mrib ] quit

# Create VLAN 20, and assign GigabitEthernet 1/0/2 to the VLAN.

[SwitchA] vlan 20 [SwitchA-vlan20] port gigabitethernet 1/0/2 [SwitchA-vlan20] quit

# Assign an IP address to VLAN-interfac e 20, and enabl e PIM-DM on the interface.

[SwitchA] in terface vlan-interface 20 [SwitchA-Vlan-interface20] ip address 1.1.1.2 24 [SwitchA-Vlan-interface20] pim dm [SwitchA-Vlan-interface20] quit

# Create VLAN 10.

[SwitchA] vlan 10 [SwitchA-vlan10] quit

# Configure GigabitEthernet 1/0/1 as a hybrid port, and assign the port to VLAN 10 as a tagged VLAN member.

[SwitchA] in terface gigabitethernet 1/0/1 [SwitchA-GigabitEthernet1/0/1] port link-type hybrid [SwitchA-GigabitEthernet1/0/1] port hybri d vlan 10 tagged [SwitchA-GigabitEthernet1/0/1] quit

# Assign an IP address to VLAN-interface 10, and enable IGMP on the interface.

[SwitchA] in terface vlan-interface 10 [SwitchA-Vlan-interface10] ip address 10.110.1.1 24 [SwitchA-Vlan-interface10] igmp enable [SwitchA-Vlan-interface10] quit

2. Configure Switch B: # Enable IGMP snooping globally.

<SwitchB> system-view [SwitchB] ig mp-snooping [SwitchB-igmp-snooping] quit

# Create VLAN 2, assign GigabitEthernet 1/0/2 to the VLAN, an d enable IGMP snooping for the VLAN.

[SwitchB] vlan 2 [SwitchB-vlan2] port gigabitethernet 1/0/2 [SwitchB-vlan2] igmp-snoop ing enable [SwitchB-vlan2] quit

# Create VLAN 3, assign GigabitEthernet 1/0/3 to the VLAN, and enable IGMP snooping in the VLAN.

[SwitchB] vlan 3 [SwitchB-vlan3] port gigabitethernet 1/0/3 [SwitchB-vlan3] igmp-snoop ing enable [SwitchB-vlan3] quit

# Create VLAN 4, assign GigabitEthernet 1/0/4 to the VLAN, and enable IGMP snooping in the VLAN.

[SwitchB] vlan 4 [SwitchB-vlan4] port gigabitethernet 1/0/4 [SwitchB-vlan4] igmp-snoop ing enable [SwitchB-vlan4] quit

# Create VLAN 10, and enable IGMP snooping for the VLAN.

[SwitchB] vlan 10 [SwitchB-vlan10] igmp-snooping enable [SwitchB-vlan 10] quit

# Configure GigabitEthernet 1/0/1 as a hybrid port, and assign the port to VLAN 10 as a tagged VLAN member.

[SwitchB] in terface gigabitethernet 1/0/1 [SwitchB-GigabitEthernet1/0/1] port link-type hybrid [SwitchB-GigabitEthernet1/0/1] port hybrid vlan 10 tagged [SwitchB-GigabitEthernet1/0/1] quit

# Configure VLAN 10 as a multicast VLAN, and assign VLAN 2 through VLAN 4 as sub-VLANs to multicast VLAN 10.

[SwitchB] multicast-vlan 10 [SwitchB-mvlan-10] subvl an 2 to 4 [SwitchB-mvlan-10] quit

Verifying the configuration

# Display information about all multicast VLANs on Switch B.

[SwitchB] display multicast-vlan Total 1 multicast VLANs.

Multicast VLAN 10: Sub-VLAN list(3 in total): 2-4 Port list(0 in total):

# Display information about multicast groups in multicast VLANs on Switch B.

•

Source

Receiver

Host A

VLAN 2

GE1

/0/

GE1

/0/

1/0/4

Switch B

IGMP querier

Switch A

1.1.

1/24

Receiver

Host B

VLAN 3

Receiver

Host C

VLAN 4

1/0/

GE1/0

Vlan

-int10

10.110.

1.1

/24

GE1/

0/2

Vlan-

int20

1.1

.1.

2/24

[SwitchB] di splay multicast-vlan group Total 1 entrie s.

Multicast VLAN 10 : Total 1 entries. (0.0.0.0, 224. 1.1.1) Sub-VLANs (3 in total) : VLAN 2 VLAN 3 VLAN 4

The output shows that m ulticast gr oup 224. 1.1.1 be longs to m ulticast VLAN 10. Mult icast VL AN 10 contains sub-VLANs VLAN 2 through VLAN 4. Switch B will replicate the multicast data of VLAN 10 to VLAN 2 through VLAN 4.

Port-based multicast VLAN configuration example

Network requirements

As shown in Figure 23:

Layer 3 device Switch A runs IGMPv2 and acts as the IGMP querier. Layer 2 device Switch B

runs IGMPv2 snooping.

The multicast source sends multicast data to multicast group 224.1.1.1. Receivers Host A, Host

B, and Host C belong to VLAN 2, VLAN 3, and VLAN 4, respectively.

Configure a port-based multicast VLAN on Switch B to meet the following requirements:

Switch A sends multicast data to Switch B through the multicast VLAN. Switch B forwards the multicast data to the receivers in different user VLANs.

Figure 23 Network diagram

Configuration procedure

1. Configure Switch A:

# Enable IP multicast routing.

<SwitchA> sy stem-view

[SwitchA] mu lticast routing [SwitchA-mrib ] quit

# Create VLAN 20, and assign GigabitEthernet 1/0/2 to the VLAN.

[SwitchA] vlan 20 [SwitchA-vlan20] port gigabitethernet 1/0/2 [SwitchA-vlan20] quit

# Assign an IP address to VLAN-interfac e 20, and enabl e PIM-DM on the interface.

[SwitchA] in terface vlan-interface 20 [SwitchA-Vlan-interface20] ip address 1.1.1.2 24 [SwitchA-Vlan-interface20] pim dm [SwitchA-Vlan-interface20] quit

# Create VLAN 10, and assign GigabitEthernet 1/0/1 to the VLAN.

[SwitchA] vlan 10 [SwitchA-vlan10] port gigabitethernet 1/0/1 [SwitchA-vlan 10] quit

# Assign an IP address to VLAN-interface 10, and enable IGMP on the interface.

[SwitchA] in terface vlan-interface 10 [SwitchA-Vlan-interface10] ip address 10.110.1.1 24 [SwitchA-Vlan-interface10] igmp enable [SwitchA-Vlan-interface10] quit

2. Configure Switch B: # Enable IGMP snooping globally.

<SwitchB> sy stem-view [SwitchB] ig mp-snooping [SwitchB-igmp-snooping] quit

# Create VLAN 10, assign GigabitEthernet 1/0/1 to the VLAN, and enable IGMP snooping for the VLAN.

[SwitchB] vlan 10 [SwitchB-vlan 10] port gigabitetherne t 1/0/1 [SwitchB-vlan 10] igmp-snoopin g enable [SwitchB-vlan 10] quit

# Create VLAN 2, and enable IGMP snooping for the VLAN.

[SwitchB] vlan 2 [SwitchB-vlan2] igmp-snooping enab le [SwitchB-vlan2] quit

# Create VLAN 3, and enable IGMP snooping for the VLAN.

[SwitchB] vlan 3 [SwitchB-vlan3] igmp-snooping enab le [SwitchB-vlan3] quit

# Create VLAN 4, and enable IGMP snooping for the VLAN.

[SwitchB] vlan 4 [SwitchB-vlan4] igmp-snooping enab le [SwitchB-vlan4] quit

# Configure GigabitEthernet 1/0/2 as a hybrid port, and configure VLAN 2 as the PVID of the hybrid port.

[SwitchB] in terface gigabitethernet 1/0/2 [SwitchB-GigabitEthernet1/0/2] port link-t ype hybrid [SwitchB-Giga bitEthernet1/0 /2] port hybrid pvid vlan 2

# Assign GigabitEthernet 1/0/2 to VLAN 2 and VLAN 10 as an untagged VLAN member.

[SwitchB-Giga bitEthernet1/0 /2] port hybrid vlan 2 untagged [SwitchB-Giga bitEthernet1/0 /2] port hybrid vlan 10 untagged [SwitchB-GigabitEthernet1/0/2] quit

# Configure GigabitEthernet 1/0/3 as a hybrid port, and configure VLAN 3 as the PVID of the hybrid port.

[SwitchB] in terface gigabitethernet 1/0/3 [SwitchB-GigabitEthernet1/0/3] port link-t ype hybrid [SwitchB-Giga bitEthernet1/0 /3] port hybrid pvid vlan 3

# Assign GigabitEthernet 1/0/3 to VLAN 3 and VLAN 10 as an untagged VLAN member.

[SwitchB-Giga bitEthernet1/0 /3] port hybrid vlan 3 untagged [SwitchB-Giga bitEthernet1/0 /3] port hybrid vlan 10 untagged [SwitchB-GigabitEthernet1/0/3] quit

# Configure GigabitEthernet 1/0/4 as a hybrid port, and configure VLAN 4 as the PVID of the hybrid port.

[SwitchB] in terface gigabitethernet 1/0/4 [SwitchB-GigabitEthernet1/0/4] port link-t ype hybrid [SwitchB-Giga bitEthernet1/0 /4] port hybrid pvid vlan 4

# Assign GigabitEthernet 1/0/4 to VLAN 4 and VLAN 10 as an untagged VLAN member.

[SwitchB-Giga bitEthernet1/0 /4] port hybrid vlan 4 untagged [SwitchB-Giga bitEthernet1/0 /4] port hybrid vlan 10 untagged [SwitchB-GigabitEthernet1/0/4] quit

# Configure VLAN 10 as a multicast VLAN.

[SwitchB] multicast-vlan 10

# Assign GigabitEthernet 1/0/2 and GigabitEthernet 1/0/3 to VLAN 10.

[SwitchB-mvlan-10] port gigabitethernet 1/0/2 to gigabitethernet 1/0/3 [SwitchB-mvlan-10] quit

# Assign GigabitEthernet 1/0/4 to VLAN 10.

[SwitchB] interface gigabitether net 1/0/4 [SwitchB-GigabitEthernet1/0/4] port multicast-vlan 10 [SwitchB-GigabitEthernet1/0/4] quit

Verifying the configuration

# Display information about multicast VLANs on Switch B.

[SwitchB] display multicast-vlan Total 1 multicast VLANs.

Multicast VLAN 10: Sub-VLAN list(0 in total): Port list(0 in total): GE1/0/2 GE1/0/3 GE1/0/4

# Display dynamic IGMP snooping group entries on Switch B.

[SwitchB] di splay igmp-snooping group Total 1 entrie s.

VLAN 10: Total 1 en tries.

(0.0.0.0, 224. 1.1.1) Host slots (0 in total): Host ports (3 in total): GE1/0/2 (00:03:23) GE1/0/3 (00:04:07) GE1/0/4 (00:04:16)

The output shows t hat IGMP snoopi ng maintains the u ser ports in the m ulticast VLAN ( VLAN 10). Switch B will forward the multicast data of VLAN 10 through these user ports.

•

Configuring multicast routing and forwarding

Overview

The following tables are involved in multicast routing and forwarding:

Multicast routing table of each multicast routing protocol, such as the PIM routing table. General multicast routing table that summarizes multicast routing information generated by

different multicast routing protocols. The multicast routing information from multicast sources to multicast groups are stored in a set of (S, G) routing entries.

Multicast forwarding table that guides multicast forwarding. The optimal routing entries in the

multicast routing table are added to the multicast forwarding table.

RPF check mechanism

A multicast routing protocol us es reverse path forwarding (RPF) chec k to ensure the multicast dat a delivery along the correct path and to avoid data loops.

RPF check process

A multicast router performs the RPF check on a multicast packet as follows:

1. The router chooses an optimal route back to the packet source separately from the unicast, MBGP, and static multicast routing tables.

The term "packet source" means different things in different situations:

 For a packet that travels along the SPT, the packet source is the multicast source.  For a packet that travels along the RPT, the packet source is the RP.  For a bootstrap message originated from the BSR, the packet source is the BSR.

For more information about the concepts of SPT, RPT, source-side RPT, RP, and BSR , see "Configuring PIM."

2. The router selects one of the three optimal routes as the RPF route as follows:

 If the router uses the longest prefix match principle, the route with the highest subnet mask

becomes the RPF route. If the routes have the same mask, the route with the highest route preference becomes the RPF route. If the routes have the same route preference, the unicast route becomes the RPF route.

For more information about the route preference, see Layer 3—IP Routing Configuration Guide.

 If the router does not use the longest prefix match principle, the route with the highest route

preference becomes the RPF route. If the routes have the same preference, the unicast route becomes the RPF route.

The RPF route contains the RPF interface and RPF neighbor information.

 If the RPF route is a unicast route or MBGP route, the outgoing interface is the RPF

interface and the next hop is the RPF neighbor.

 If the RPF route is a static multicast route, the RPF interface and RPF neighbor are

specified in the route.

3. The router checks whether the packet arrived at the RPF interface. If yes, the RPF check succeeds and the packet is forwarded. If not, the RPF check fails and the packet is discarded.

•

Source

192.168.0.1/24

Receiver

Device A

Device B

Device C

GE1/0/2

GE1/0/1

Multicast packets

Destination/Mask

IP routing table on Device C

192.168.0.0/24

Interface

GE1/0/2

RPF check implementation in multicast

Implementing an RPF check on each received multicast packet brings a big burden to the router. The use of a multicast forward ing tab le is the so lutio n to thi s issue. When the router creates a multic ast forwarding entry for an (S, G) packet, it sets the RPF interface of the packet as the incoming interface of the (S, G) entry. After the router receives another (S, G) packet, it looks up the multicast forwarding table for a matching (S, G) entry:

If no match is found, the router first determines the RPF route back to the packet source and the

RPF interface. 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 out of all the 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 matching forwarding entry contains the receiving interface, the

router forwards the packet out of all the outgoing interfaces.

If a match is found but the matching forwarding entry does not contain the receiving interface,

the router determines the RPF route back to the packet source. Then, the router performs one of the following actions:

 If the RPF interface is the incoming interface, it means that the forwarding entry is correct

but the packet traveled along a wrong path. The packet fails the RPF check, and the router discards the packet.

 If the RPF interface is not the incoming interface, it means that the forwarding e ntr y 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 out of all outgoing interfaces. Otherwise, it discards the packet.

RPF check process

Figure 24 RPF check process

As shown in Figure 24, assume that unicast routes are available on the network, MBGP is not configured, and no static multicast routes have be en configured on Device C. Multicast packets travel along the SPT from the multicast sourc e to the receiver s. The multicas t forwarding tabl e on Device C contains the (S, G) entry, with GigabitEthernet 1/0/2 as the incoming interface.

If a multicast packet arrives at Device C on GigabitEthernet 1/0/2, the receiving interface is the

incoming interface of the (S, G) entry. Device C forwards the packet out of all outgoing interfaces.

•

Receiver

Device A

Device B

Device C

GE1/0/2

GE1/0/1

1.1.1.1/24

Multicast packets

Source

192.168.0.1/24

Receiver

GE1/0/1

1.1.1.2/24

Static multicast route

Source/Mask

Static multicast routing table on Device C

192.168.0.0/24

Interface

GE1/0/1

RPF neighbor/Mask

1.1.1.1/24

If a multicast packet arrives at Device C on GigabitEthernet 1/0/1, the receiving interface is not

the incoming interface of the (S, G) entry . Device C searches its unicast routing table and finds that the outgoing interface to the source (the RPF interface) is GigabitEthernet 1/0/2. In this case, the (S, G) entry is correct, but the packet traveled along a wrong path. The packet fails the RPF check, and Device C discards the packet.

Static multicast routes

Depending on the a pplication environment, a stat ic multicast route can change an RPF route or 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. Y ou can configure a static multicast route for a m ulticast source to change th e RPF route. As a result, the rout er creates a transmission path for multicast traffic that is different from the transmission path for unicast traffic.

Figure 25 Changing an RPF route

As shown in Figure 25, when no static multicast route is configured, Device C's RPF neighbor on the path back to the source is Device A. The multicast data from the source travels through Device A to Device C. You can configure a static multicast route on Device C and specify Device B as Devi ce C's RPF neighbor on the path back to the sour ce. T he m ulticast data f rom the s ource tr avels alo ng the path: Device A to Device B and then to Device C.

Creating an RPF route

When a unicast route is blocked, multicast forwarding might be stopped due to lack of an RPF route. You can configure a static m ulticast route to create an RPF r oute. In this way, a multicast routing entry is created to guide multicast forwarding.

•

NOTE:

A static multicast route is effective only on the multicast router on which it is configured, and will not be advertised throughout the network or redistributed to other routers.

GE1/0/1

GE1/0/2

/24

GE1/0/2 2

GE1

2.2.2.1/24

Source

192.

168.0.1/24

Source/Mask

Static multicast routing table on Device C

192.

168

Interface

RPF neighbor

/Mask

/24

Source/Mask

Static multicast routing table on Device D

192.

168.

Interface

RPF neighbor/

Mask

OSPF domain

RIP domain

Device A Device B

Device C

Device D

Receiver

Multicast packets Static multicast route

Figure 26 Creating an RPF route

As shown in Figure 26, the RIP domain and the OSPF domain are unicast isolated from each other. For the receiver hosts in the OSPF domain to receive multicast packets from the multicast source in the RIP domain, you must configure Device C and Device D as follows:

On Device C, configure a static multicast route for the multicast source and specify Device B as

the RPF neighbor.

On Device D, configure a static multicast route for the multicast source and specify Device C as

the RPF neighbor.

Multicast forwarding across unicast subnets

Routers forward the multicast data from a multicast source hop by hop along the forwarding tree, but some routers might not support multicast protocols in a network. When the multicast data is forwarded to a router that does not support IP multicast, the forwarding path is blocked. In this case, you can enable multicas t forwarding acros s two unicast subne ts by establishin g a tunnel bet ween the routers at the edges of the two unicast subnets.

Tasks at a glance

NOTE:

The device can interfaces information Services Configuration Guide.

Step

Command

Remarks

Tunnel

Unicast device

Multicast device

Device ASource ReceiverDevice B

Figure 27 Multicast data transmission through a tunnel

As shown in Figure 27, a tunnel is established between the multicast routers Device A and Device B. Device A encapsulates the multicast data in u nicast IP packets, and forwards them to Device B across the tunnel through unicast routers. Then, Device B strips off the unicast IP header and continues to forward the multicast data to the receiver.

To use this tunnel only for multicast traffic, configure the tunnel as the outgoing interface onl y for multicast routes.

Configuration task list

(Required.) Enabling IP multicast rou ting (Optional.) Configuring multicast routing and forwarding:

• (Optional.) Configuring static multicast routes

• (Optional.) Specifying the longest prefix match principle

• (Optional.) Configurin g multicast load splitting

• (Optional.) Configuring a multicast forwarding boundary

• (Optional.) Enabling multicast forwarding between sub-VLANs of a super VLAN

route and forward multicast data only through the primary IP addresses of

, rather than their secondary addresses or unnumbered IP addr ess es . For more

about primary and secondary IP addresses, and IP unnumbered, see Layer 3—IP

Enabling IP multicast routing

Enable IP multicast routing before you configure an y Layer 3 multicast functionality on the public network or VPN instance.

To enable IP multicast routing:

1. Enter system view.

2. Enable IP multicast routing

and enter MRIB view.

system-view multicast routing [ vpn-instance

vpn-instance-name ]

N/A By default, IP multicast routing is

disabled.

•

Step

Command

Remarks

Step

Command

Remarks

Configuring multicast routing and forwarding

Before you configure multicast routing and forwarding, complete the following tasks:

Configure a unicast routing protocol so that all devices in the domain can interoperate at the

network layer.

Enable PIM-DM or PIM-SM.

Configuring static multicast routes

T o configure a static multicast route for a given multicast source, you can specify an RPF interface or an RPF neighbor for the multicast traffic from that source.

To configure a static multicast route:

1. Enter system view.

2. Configure a static

multicast route.

3. (Optional.) Delete static multicast routes.

system-view ip rpf-route-static

vpn-instance-name ] source-address { mask-length | mask } { rpf-nbr-address | interface-type interface-number }

preference

[

• Delete a specific static multicast route: undo ip rpf-route-static [ vpn-instance

vpn-instance-name ] source-address { mask-length | mask } { rpf-nbr-address | interface-type interface-number }

• Delete all static multicast routes:

delete ip rpf-route-static [ vpn-instance

vpn-instance-name ]

preference ]

vpn-instance

[

Specifying the longest prefix mat c h principle

Y ou can enable the device to use the longest prefix match principle for RPF route selection. For more information about RPF route selection, see "RPF check process."

To specify the longest prefix match principle:

N/A

By default, no static multicast routes exist.

N/A

1. Enter system view.

2. Enter MRIB view.

3. Specify the longest prefix

match principle.

system-view multicast routing

vpn-instance-name ]

longest-match

[

vpn-instance

N/A

By default, the route preference principle is used.

Step

Command

Remarks

TIP

You do not need to enable IP multicast routing before this configuration.

Step

Command

Remarks

Step

Command

Remarks

system-view

Configuring mu l ticast load split ting

You can enable the device to split multiple data flows on a per-source basis or on a per-source-and-group basis. This optimizes the traffic delivery.

To configure multicast load splitting:

1. Enter system view.

2. Enter MRIB view.

3. Configure multicast load

splitting.

system-view multicast routing

vpn-instance-name ]

load-splitting source-group

source

{

ucmp

[

vpn-instance

}

N/A

By default, multicast load splitting is disabled.

This command does not take effect on BIDIR-PIM.

Configuring a multicast forwarding boundary

You can configure an interface as a m ulticas t f or wardi ng bou ndary for a multicast group rang e. The interface cannot receive or forward multicast packets for the group range.

To configure a multicast forwarding boundary:

1. Enter system view.

2. Enter interface view.

3. Configure the interface as a

multicast forwarding boundary for a multicast group range.

system-view interface

interface-number

multicast boundary

group-address { mask-length | mask }

interface-type

N/A

By default, an interface is not a multicast forwarding boundary.

Enabling multicast forwarding between sub-VLANs of a super VLAN

A super VLAN is associated with multiple sub-VLANs. Sub-VLA Ns are isolated with eac h other at Layer 2. For information about the super VLAN and sub-VLANs, see Layer 2—LAN Switching Configuration Guide.

To enable multicast forwarding between sub-VLANs that are associate d with a super VLAN:

1. Enter system view.

2. Enter VLAN interface view.

interface vlan-interface

interface-number

N/A

Step

Command

Remarks

CAUTION: The reset commands might cause multicast data transmission failures.

Task

Command

outgoing-interface

{

exclude | include | match

}

3. Enable multicast forwarding between sub-VLANs that are associated with a super VLAN.

4. Clear all multicast forwarding entries with the super VLAN interface as the incoming interface.

multicast forwarding supervlan community

reset multicast [ vpn-instance

vpn-instance-name ]

forwarding-table

{ { source-address [ { mask-length | mask } ] | group-address [ { mask-length | mask } ] |

incoming-interface

{ interface-type interface-number } } * |

mask

all }

By default, multicast data cannot be forwarded between sub-VLANs that are associated with a super VLAN.

N/A

Displaying and maintaining multicast routing and forwarding

Execute display commands in any view and reset commands in user view.

Display information about the interfaces maintained by the MRIB.

Display multicast boundary information.

(In standalone mode.) D isp lay multicast fast forwarding entries.

(In IRF mode.) Display multicast fast forwarding entries.

(In standalone mode.) Display DF information.

(In IRF mode.) Display DF information.

(In standalone mode.) Display statistics for multicast forwarding events.

(In IRF mode.) Display statistics for multicast forwarding events.

(In standalone mode.) Display multicast forwarding entries.

display mrib [ vpn-instance

[ interface-type interface-number ]

display multicast [ vpn-instance boundary

interface-type interface-number ]

display multicast fast-forwarding cache

slot

[

display multicast fast-forwarding cache

chassis

[

display multicast forwarding df-info

slot-number ]

display multicast forwarding df-info

chassis-number

display multicast [ vpn-instance forwarding event [ slot

display multicast [ vpn-instance forwarding event [ chassis

display multicast forwarding-table

mask } ] | group-address [

incoming-interface

[ group-address [ mask-length | mask ] ] [

vpn-instance

[

slot-number ]

chassis-number

vpn-instance

[

vpn-instance

[

[ rp-address ] [

vpn-instance

[

[ rp-address ] [

slot

slot-number ]

vpn-instance

[ [ source-address [

interface-type interfac e-number |

vpn-instance-name ]

[ source-address | group-address ] *

slot

slot-number ]

chassis-number

mask

{ mask-length | mask } ] |

interface

vpn-instance-name ]

interface

vpn-instance-name ]

verbose

vpn-instance-name ]

verbose

vpn-instance-name ]

mask

slot

] [

chassis

] [

slot

slot-number ]

{ mask-length |

Task

Command

interface-type interface-number |

slot

slot-number |

statistics

]

NOTE:

•

cleared.

(In IRF mode.) Display multicast forwarding entries.

(In standalone mode.) D isplay inf ormation about the DF list in the multicast forwarding table.

(In IRF mode.) Display informa tion abou t the DF list in the multicast forwarding table.

Display multicast routing entries.

Display static multicast routing entries.

Display RPF information for a multicast source.

(In standalone mode.) Clear multicast fast forwarding entries.

display multicast forwarding-table

mask } ] | group-address [

chassis incoming-interface outgoing-interface

interface-type interface-number |

display multicast forwarding-table df-list

slot-number ]

display multicast forwarding-table df-list

[

display multicast [ vpn-instance routing-table

| group-address [

incoming-interface outgoing-interface

interface-type interface-number ] *

display multicast [ vpn-instance routing-table static

display multicast [ vpn-instance rpf-info

reset multicast [ vpn-instance fast-forwarding cache all

chassis-number

chassis

chassis-number

source-address [ group-address ]

slot

} [

slot-number ]

vpn-instance

[ [ source-address [

mask

{ mask-length | mask } ] |

slot

slot-number |

interface-type interfac e-number |

exclude | include | match

{

vpn-instance

[

[ group-address ] [

vpn-instance

[

[ group-address ] [

slot

slot-number ]

[ source-address [

mask

{ mask-length | mask } ] |

interface-type interfac e-number |

exclude | include | match

{

[ source-address { mask-length | mask } ]

vpn-instance-name ]

{ { source-address | group-address } * |

vpn-instance-name ]

mask

{ mask-length |

}

statistics

vpn-instance-name ]

mask

vpn-instance-name ]

] *

verbose

{ mask-length | mask } ]

}

] [

]

slot

(In IRF mode.) Clear multicast fast forwarding entries.

Clear statistics for multicast for w ar ding events.

Clear multicast forwarding entries.

Clear multicast routing entries.

reset multicast fast-forwarding cache all

chassis

} [

reset multicast forwarding event

reset multicast forwarding-table

mask } ] | group-address [

incoming-interface reset multicast

routing-table

mask } ] | group-address [

incoming-interface

vpn-instance

[

{ { source-address | group-address } * |

chassis-number

vpn-instance

[

vpn-instance

[

{ { source-address [

{ interface-type interface-number } } * |

vpn-instance

[

{ { source-address [

interface-type interfac e-number } * |

vpn-instance-name ]

slot

slot-number ]

vpn-instance-name ]

mask

{ mask-length |

mask

{ mask-length | mask } ] |

vpn-instance-name ]

mask

{ mask-length |

mask

{ mask-length | mask } ] |

When you clear a multicast routing entry, the associated multicast forwarding entry is also

cleared.

When you clear a multicast forwarding entry, the associated multicast routing entry is also

all

}

•

Static multicast route

Switch A Switch B

Switch C

Vlan-int102

30.1.1.2/24

Vlan-int103

40.1.1.2/24

Vlan

-int200

50.1.1.1/24

Vlan-int103

40.1.

1.1/

Vlan-int101

20.1.1.2/24

Vlan-int101

20.1.1.1/24

Vlan-int102

30.1

.1.

1/24

Vlan-

int100

10.1.1.1/24

Source Receiver

50.1.1.100/

24 10.1.1.100/24

PIM-DM

Configuration examples

Changing an RPF route

Network requirements

As shown in Figure 28:

PIM-DM runs on the network. All switches on the network support multicast. Switch A, Switch B and Switch C run OSPF. Typically, the receiver host can receive the multicast data from Source through the path: Switch

A to Switch B, which is the same as the unicast route.

Configure the switches so that the multicast data from Source travels to the receiver through the path: Switch A to Switch C to Switch B. This is different from the unicast route.

Figure 28 Network diagram

Configuration procedure

1. Assign an IP address and subnet mask for each interface, as shown in Figure 28. (Details not shown.)

2. Configure OSPF on the switches in the PIM-DM domain. (Details not shown.)

3. Enable IP multicast routing, and enable IGMP and PIM-DM:

# On Switch B, enable IP multicast routing.

<SwitchB> sy stem-view [SwitchB] mu lticast routing [SwitchB-mrib] quit

# Enable IGMP on the receiver-side interface VLAN-interface 100.

[SwitchB] in terface vlan-interface 100 [SwitchB-Vlan-interface100] igmp enable [SwitchB-Vlan-interface10 0] quit

•

# Enable PIM-DM on other interf ac es .

[SwitchB] in terface vlan-interface 101 [SwitchB-Vlan-interface10 1] pim dm [SwitchB-Vlan-interface10 1] quit [SwitchB] in terface vlan-interface 102 [SwitchB-Vlan-interface10 2] pim dm [SwitchB-Vlan-interface10 2] quit

# On Switch A, enable IP multicast routing.

<SwitchA> sy stem-view [SwitchA] mu lticast routing [SwitchA-mrib] quit

# Enable PIM-DM on each interface.

[SwitchA] in terface vlan-interface 200 [SwitchA-Vlan-interface20 0] pim dm [SwitchA-Vlan-interface20 0] quit [SwitchA] in terface vlan-interface 102 [SwitchA-Vlan-interface10 2] pim dm [SwitchA-Vlan-interface10 2] quit [SwitchA] in terface vlan-interface 103 [SwitchA-Vlan-interface10 3] pim dm [SwitchA-Vlan-interface10 3] quit

# Enable IP multicast routing and PIM-DM on Switch C in the same way Switch A is configured. (Details not shown.)

4. Display RPF information for Source on S witc h B.

[SwitchB] di splay multicast rpf-info 50.1.1.100 RPF informatio n 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: igp Route sele ction rule: preference-preferred Load splitting rule: disable

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-stati c 50.1.1.100 24 20.1. 1.2

Verifying the configuration

# Display RPF information for Sourc e on Switc h B.

[SwitchB] di splay multicast rpf-info 50.1.1.100 RPF informatio n 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 stat ic Route sele ction rule: preference-preferred Load splitting rule: disable

The output shows the following information:

The RPF route on Switch B is the configured static multicast route.

•

Switch A Switch B

Switch C

Vlan-int102 30

.1.1.2/24

Vlan-int101

20.1

1.2/24

Vlan-int101 20

.1.

1/24

Vlan-int

102

30.1.1.1/24

Source 1Source

2 Receiver

40.1.1.100/24 10.1.1.100/24

Static multicast route

Vlan-int200

.1.1

.1/24

Vlan-int100 10

.1.

1.1

/24

OSPF domain

PIM-DM

50.1.1.100/24

Vlan-int300

50.1.1.1/24

The RPF neighbor of Switch B is Switch C.

Creating an RPF route

Network requirements

As shown in Figure 29:

PIM-DM runs on the network. All switches on the network support IP multicast. Switch B and Switch C run OSPF, and have no unicast routes to Switch A. Typically, the receiver host receives the m ultic ast dat a f rom Source 1 in the OSPF domain.

Configure the switches so that the receiver host receives m ulticast data from Source 2, which is outside the OSPF domain.

Figure 29 Network diagram

Configuration procedure

1. Assign an IP address and subnet mask for each interface, as shown in Figure 29. (Details not

shown.)

2. Configure OSPF on Switch B and Switch C. (Details not shown.)

3. Enable IP multicast routing, and enable IGMP and PIM-DM:

# On Switch C, enable IP multicast routing.

<SwitchC> sy stem-view [SwitchC] mu lticast routing [SwitchC-mrib] quit

# Enable IGMP on the receiver-side interface VLAN-interface 100.

[SwitchC] in terface vlan-interface 100 [SwitchC-Vlan-interface100] igmp enable [SwitchC-Vlan-interface10 0] quit

# Enable PIM-DM on VLAN-interface 101.

[SwitchC] in terface vlan-interface 101 [SwitchC-Vlan-interface10 1] pim dm [SwitchC-Vlan-interface10 1] quit

# On Switch A, enable IP multicast routing.

<SwitchA> sy stem-view [SwitchA] mu lticast routing [SwitchA-mrib] quit

# Enable PIM-DM on each interface.

[SwitchA] in terface vlan-interface 300 [SwitchA-Vlan-interface30 0] pim dm [SwitchA-Vlan-interface30 0] quit [SwitchA] in terface vlan-interface 102 [SwitchA-Vlan-interface10 2] pim dm [SwitchA-Vlan-interface10 2] quit

# Enable IP multicast routing and PIM-DM on Switch B in the same way Switch A is configured. (Details not shown.)

4. Display RPF information for Source 2 on Switch B and Switch C.

[SwitchB] di splay multicast rpf-info 50.1.1.100 [SwitchC] di splay multicast rpf-info 50.1.1.100

No output is displayed because no RPF routes to Source 2 exist 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 RPF information for Source 2 on Sw itc h B.

[SwitchB] di splay multicast rpf-info 50.1.1.100 RPF informatio n 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 stat ic Route sele ction rule: preference-preferred Load splitting rule: disable

# Display RPF information for Source 2 on Switch C.

[SwitchC] di splay multicast rpf-info 50.1.1.100 RPF informatio n 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 stat ic Route sele ction rule: preference-preferred Load splitting rule: disable

The output shows that th e R PF rout es to Source 2 exist on Switc h B a nd S witch C . The routes are the configured static routes.

Multicast forwarding over a GRE tunnel

Network requirements

As shown in Figure 30:

•

Multicast router

Switch A

Vlan-int101

20.1.1.1/24

Vlan-int102

30.1.1.1/24

Vlan-int102

30.1.1.2/24

Vlan-int101

20.1.1.2/24

Source Receiver

40.1.1.100/24

Vlan-int200

40.1.1.1/24

10.1.1.100/24

Vlan-int100

10.1.1.1/24

GRE tunnel

Tunnel1

50.1.1.1/24

Tunnel1

50.1.1.2/24

Unicast router

Switch B

Multicast router

Switch C

Member port of a service loopback group

GE1/0/3 GE1/0/3

Multicast routing and PIM-DM are enabled on Switch A and Switch C. Switch B does not support multicast. Switch A, Switch B, and Switch C run OSPF.

Configure the switches so that the receiver host can receive the multicast data from Source.

Figure 30 Network diagram

Configuration procedure

1. Assign an IP address and subnet mask for each interface, as shown in Figure 30. (Details not

shown.)

2. Configure OSPF on all the switches. (Details not shown.)

3. Configure a GRE tunnel:

# On Switch A, create service loopback group 1, and specify the unicast tunnel service for the group.

<SwitchA> system-view [SwitchA] service-loopba ck group 1 type tunnel

# Add GigabitEthernet 1/0/3 to service loopback group 1. (GigabitEthernet 1/0/3 does not belong to VLAN 100 or VLAN 101.)

[SwitchA] in terface gigabitethernet 1/0/3 [SwitchA-Giga bitEthernet1/0 /3] port service -l oo pback group 1 [SwitchA-Giga bitEthernet1/0 /3] quit

# Create a GRE tunnel interface Tunnel 1, and specify the tunnel mode as GRE/IPv4.

[SwitchA] interface tunnel 1 mode gre

# Assign an IP address to interface Tunnel 1, and specify its source and destination addresses.

[SwitchA-Tunnel1] ip address 50.1.1.1 24 [SwitchA-Tunnel1] source 20.1.1.1 [SwitchA-Tunnel1] destination 30.1.1.2 [SwitchA-Tunnel1] quit

# On Switch C, create service loopback group 1, and specify the unicast tunnel service for the group.

<SwitchC> system-view [SwitchC] service-loopback grou p 1 type tunnel

# Add GigabitEthernet 1/0/3 to service loopback group 1. GigabitEthernet 1/0/3 does not belong to VLAN 200 or VLAN 102.

[SwitchC] in terface gigabitethernet 1/0/3 [SwitchC-GigabitEthernet1/0 /3] port service -l oopback group 1 [SwitchC-GigabitEthernet1/0 /3] quit

# Create a GRE tunnel interface Tunnel 1, and specify the tunnel mode as GRE/IPv4.

[SwitchC] interface tunnel 1 mode gre

# Assign an IP address for interface Tunnel 1, and specify its source and destination addresses.

[SwitchC-Tunnel1] ip address 50.1.1.2 24 [SwitchC-Tunnel1] source 30.1.1.2 [SwitchC-Tunnel1] destination 20.1.1.1 [SwitchC-Tunnel1] quit

4. Enable IP multicast routing, PIM-DM, and IGMP: # On Switch A, enable multicast routing.

[SwitchA] multicast routing [SwitchA-mrib] quit

# Enable PIM-DM on each interface.

[SwitchA] interface vlan-interface 100 [SwitchA-Vlan-interface100] pim dm [SwitchA-Vlan-interface100] quit [SwitchA] interface vlan-interface 101 [SwitchA-Vlan-interface101] pim dm [SwitchA-Vlan-interface101] quit [SwitchA] interface tunnel 1 [SwitchA-Tunnel1] pim dm [SwitchA-Tunnel1] quit

# On Switch C, enable multicast routing.

[SwitchC] mu lticast routing [SwitchC-mrib] quit

# Enable IGMP on the receiver-side interface VLAN-interface 200.

[SwitchC] in terface vlan-interface 200 [SwitchC-Vlan-interface200] igmp enable [SwitchC-Vlan-interface200] quit

# Enable PIM-DM on VLAN-interface 102.

[SwitchC] in terface vlan-interface 102 [SwitchC-Vlan-interface102] pim dm [SwitchC-Vlan-interface102] quit

# Enable PIM-DM on Tunnel 1.

[SwitchC] interface tunnel 1 [SwitchC-Tunnel1] pim dm [SwitchC-Tunnel1] quit

5. On Switch C, configure a static multicast route to Source and specify Switch A as the RPF neighbor.

[SwitchC] ip rpf-route-static 50.1.1.0 24 50.1.1.1

Verifying the configuration

# Send an IGMP report from Receiver to join multicast group 225.1.1.1. (Details not shown.) # Send multicast data from Source to multicast group 225.1.1.1. (Details not shown.) # Display PIM routing entries on Switch C.

[SwitchC] display pim routing-table Total 1 (*, G) entry ; 1 (S, G) entry

(*, 225.1.1.1)

Protocol : pim-dm, Flag: WC UpTime: 00 :04:25 Upstream interface: NULL Upstream neighbor: NULL RPF prime neighbor: NU LL Downstre am interface(s) information: Total numb er of downstreams: 1 1: Vlan-interface200 Protocol: igmp, UpTime: 00 :0 4:25, Expires: -

(10.1.1.100, 225.1.1.1) Protocol : pim-dm, Flag: ACT UpTime: 00 :06:14 Upstream interface: Tunnel1 Upstream neighbor: 50.1.1.1 RPF prime neighbor: 50.1.1.1 Downstre am interface(s) information: Total numb er of downstreams: 1 1: Vlan-interface200 Protocol: pim-dm, UpTime: 00:04:25, Expires: -

The output shows that Switch A is the RPF neighbor of Switch C and the multicast data from Switch A is delivered over the GRE tunnel to Switch C.

Troubleshooting multicast routing and forwarding

Static multicast route failure

Symptom

No dynamic routing protocol is enabled on the routers, and the physical status and link layer status of interfaces are both up, but the static multicast route fails.

Solution

To resolve the problem:

1. Use the display multicast routing-table static command to display information about static multicast routes. Verify that the static multicast route has been correctly configured and that the route entry exists in the static multicast routing table.

2. Check the type of the interface that connects the static multicast route to the RPF neighbor. If the interface is not a point-to-point interface, be sure to specify the address for the RPF neighbor.

3. If the problem persists, contact Hewlett Packard Enterprise Support.

•

Query Report

Host A

(G2)

Host B

(

G1)

Host C

(

G1)

Ethernet

Router A Router B

IP network

Configuring IGMP

Overview

Internet Group Management Protocol (IGMP) establishes and maintains the multicast group memberships between a Layer 3 multicast device and the hosts on the directly connected subnet.

IGMP has the following versions:

IGMPv1 (defined by RFC 1112). IGMPv2 (defined by RFC 2236). IGMPv3 (defined by RFC 3376).

All IGMP versions support the ASM model. IGMPv3 can directly implement the SSM model. IGMPv1 and IGMPv2 must work with the IGMP SSM mapping feature to implement the SSM model. For more information about the ASM and SSM models, see "Multicast overview."

IGMPv1 overview

IGMPv1 manages multicast group memberships based on the query and response mechanism. All routers that run IGMP on the sam e subnet can get IGMP mem bership report m essages (called

reports) from host s. However, only one router can act as the IGMP querier to send IG MP query messages (called quer ies). The querier elec tion mechanism determines which router acts as the IGMP querier on the subnet.

In IGMPv1, the DR elected by the multicast routing protocol (such as PIM) acts as the IGMP querier. For more information about DR, see "Configuri ng PIM ."

Figure 31 IGMP queries and reports

As shown in Figure 31, Host B and Host C are interested in the m ulticast data addressed to the multicast group G1. Host A is interested in the multicast data addressed to G2. The following process describes how the hosts join the multicast groups and how the IGMP querier (Router B in Figure 31) maintains the multicast group memberships:

1. The hosts send unsolicited IGMP reports to the multicast groups they want to join without having to wait for the IGMP queries.

2. The IGMP querier periodically multicasts IGMP queries (with the destination address of

224.0.0.1) to all hosts and routers on the local subnet.

3. After receiving a query message, the host whose report delay timer expires first sends an IGMP report to multicast group G1 to announce its membership for G1. In this example, Host B sends the report message. After receiving the report from Host B, Host C suppresses its own report for G1.

Because IGMP routers already know that G1 has a minimum of one member, other members do not need to report their memberships. This mechanism, known as the host IGMP report suppression, helps reduce traffic on the local subnet.

4. At the same time, Host A sends a report to the multicast group G2 after receiving a query.

5. Through the query and response process, the IGMP routers (Router A and Router B) determine

that the local subnet has members of G1 and G2. The multicast routing protocol (PIM, for example) on the routers generates (*, G1) and (*, G2) multicast forwarding entries, where asterisk (*) represents any multicast source. These entries are the basis for subsequent multicast forwarding.

6. When the multicast data addressed to G1 or G2 reaches an IGMP router, the router looks up the multicast forwarding table. Based on the (*, G1) or (*, G2) entries, the router forwards the multicast data to the local subnet. Then, the receivers on the subnet can receive the data.

IGMPv1 does not define a leave group message (often called a leave message). When an IGMPv1 host is leaving a multicast group, it stops sending reports to that multicast group. If the subnet has no members for a multicast group, the IGMP routers will not receive any report addressed to that multicast group. In this cas e, the r out er s clear the information for that multicas t gr oup af ter a per i od of time.

IGMPv2 enhancements

Backwards-com patible with IGMPv1, IGMPv2 has intr oduced a querier e lection mechanism and a leave-group mechanism.

Querier election mechanism

In IGMPv1, the D R elected by the Layer 3 m ulticast routing protocol (such as PIM) acts as the querier.

IGMPv2 introduced an independent querier election mechanism. The querier election process is as follows:

1. Initially, every IGMPv2 router assumes itself to be the querier. Each router sends IGMP general query messages (called general queries) to all hosts and routers on the local subnet. The destination address is 224.0.0.1 .

2. After receiving a general query, every IGMPv2 router compares the source IP address of the query with its own interface address. The router with the lowest IP address becomes the querier. All the other IGMPv2 routers become non-queriers.

3. All the non-queriers start the other querier present timer. If a router receives an IGMP query from the querier before the timer expires, it resets this timer. Otherwise, the router considers that the querier has timed out. In this case, the router initiates a new querier election process.

"Leave group" mechanism

In IGMPv1, when a host le aves a m ulticas t group, it does not s end an y notif icatio n to t he multicast routers. The multicast routers determine whether a group has members by using the maximum response time. This adds to the leave latency.

In IGMPv2, when a host is leaving a multicast group, the following process occurs:

1. The host sends a leave message to all routers on the local subnet. The destination address of leave messages is 224.0.0.2.

•

Source 2

Receiver

Host A

Host B

Host C

Packets (S1,G) Packets (S2,G)

Source 1

2. After receiving the leave message, the querier sends a configurable number of IGMP

group-specific queries to the group that the host is leaving. Both the destination address field and the group address field of the message are the address of the multicast group that is being queried.

3. One of the remaining members (if any on the subnet) in the group should send a report within the maximum response time advertised in the group-specific queries.

4. If the querier receives a report for the group before the maximum response timer expires, it maintains the memberships for the group. Otherwise, the querier assumes that the local subnet has no member hosts for the group and stops maintaining the memberships for the group.

IGMPv3 enhancements

IGMPv3 is based on and is compatible with IGMPv1 and IGMPv2. It enhances the control capabilities of hosts and the query and report capabilities of IGMP routers.

Enhancements in control capability of hosts

IGMPv3 introduced two s our ce filtering modes (Includ e and Ex clud e) . T hes e m odes allow a host to receive or reject m ulticast data fr om the s pecified m ulticast sourc es. W hen a host joins a multicas t group, one of the following occurs:

If the host expects to receive multicast data from specific sources like S1, S2, …, it sends a

report with the Filter-Mode denoted as "Include Sources (S1, S2, …)."

If the host expects to reject multicast data from specific sources like S1, S2, …, it sends a report

with the Filter-Mode denoted as "Exclude Sources (S1, S2, …)."

As shown in Figure 32, the network has two multicast sources: Sourc e 1 (S1) and Sourc e 2 (S2). Both of these sources can send multicast data to the multicast group G. Host B wants to receive the multicast data addressed to G from Source 1 but not from Source 2.

Figure 32 Flow paths of source-and-group-specific multicast traffic

In IGMPv1 or IGMP v2, Hos t B cann ot se lect m ulticas t s ources when it jo ins the multicast group G . The multicast streams from both Source 1 and Source 2 flow to Host B whether or not it needs them.

In IGMPv3, Host B ca n explicitly express that it nee ds to receive multicast data des tined to the multicast group G from Source 1 but not from Source 2.

Enhancements in query and report capabilities

IGMPv3 introduces IGMP group-and-source queries and IGMP reports carrying group records.

Query message carrying the source addresses

•

IGMPv3 is com patible with IG MP v1 and IGMP v2 and supports IGMP general queries and IGMP group-specific queries. It also introduces IGMP group-and-source-specif ic queri es .

 A general query does not carry a group address or a source address.  A group-specific query carries a group address, but no source address.  A group-and-source-specific query carries a group address and one or more source

addresses.

Reports containing multiple group records

Unlike an IGMPv1 or IGMPv2 report, an IGMPv3 report is destined to 224.0.0.22 and contains one or more group records. Each group record contains a multicast group address and a multicast source address list.

Group records include the following categories:

 IS_IN—The current filtering mode is Include. The report sender requests the multicast data

only from the sources specified in the Source Address field.

 IS_EX—The current filtering mode is Exclude. The report sender requests the multicast

data from any sources except those spec ified in the S ourc e Address field.

 TO_IN—The filtering mode has changed from Exclude to Include.  TO_EX—The filtering mode has changed from Include to Exclude.  ALLOW—The Source Address field contains a list of additional sources from which the

receiver wants to obtain data. If the current filtering mode is Include, these sources are added to the multicast source list. If the current filtering mode is Exclude, these sources are deleted from the multicast source list.

 BLOCK—The Source Address field contains a list of the sources from which the receiver no

longer wants to obtain data. If the current filtering mode is Include, these sources are deleted from the multicast source list. If the current filtering mode is Exclude, these sources are added to the m ulticas t sour c e list.

IGMP SSM mapping

An IGMPv3 host can explicitly specify multicast sources in its IGMPv3 reports. From the reports, the IGMP router can obtain the multicast source addresses and directly provide the SSM service. However, an IGMPv1 or IGMPv2 host c annot specify multicas t sources in its IGMPv1 or IG MPv2 reports.

The IGMP SSM mapping f eature enables th e IGMP router to pr ovide SSM supp ort for IGMPv1 or IGMPv2 hosts. The router translates (*, G) in IG MPv1 or IGMPv2 reports into (G, INCLUDE, ( S1, S2...)) based on the configured IGMP SSM mappings.

•

NOTE:

The IGMP SSM mapping feature does not process IGMPv3 reports.

•

IGMPv1 report IGMPv2 report IGMPv3 report

Router A

Querier

Host A (IGMPv1) Host B (IGMPv2) Host C (IGMPv3)

Receiver Receiver Receiver

SSM

Figure 33 IGMP SSM mapping

As shown in Figure 33, on an SSM network, Host A, Host B, and Host C run IGMPv1, IGMPv2, and IGMPv3, respectivel y. To provide the SSM service f or Host A and Host B, you must configure t he IGMP SSM mapping feature on Router A.

After IGMP SSM mappings are configured, Router A checks the multicas t group addres s G in the received IGMPv1 or IGMPv2 report, and performs the following operations:

If G is not in the SSM group range, Router A provides the ASM service. If G is in the SSM group range but does not match any IGMP SSM mapping, Router A drops the

report.

If G is in the SSM group range and matches IGMP SSM mappings, Router A translates (*, G) in

the report into (G, INCLUDE, (S1, S2...)) to provide SSM services.

For more information about SSM group ranges, see "Configuri ng PIM ."

IGMP proxying

As shown in Figure 34, in a simple tree-shaped topology, it is not necessary to run multicast routing protocols, such as PIM, on edge devices. Instead, you can configure IGMP proxying on these devices. With IGMP proxying configured, the edge device acts as an IGMP proxy:

For the upstream IGMP querier, the IGMP proxy device acts as a host. For the downstream receiver hosts, the IGMP proxy device acts as an IGMP querier.

HPP Enterprises FlexNetwork 7500 Configuration Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Multicast overview

Introduction to multicast

Information transmission techniques

Unicast

Broadcast

Multicast

Multicast features

Common notations in m ulticast

Multicast benefits and applications

Multicast benefits

Multicast applications

Multicast models

ASM model

SFM model

SSM model

Multicast architecture

Multicast addresses

IP multicast addresses

Ethernet multicast MAC addresses

Multicast protoc ol s

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 ports

Router ports

Member ports

How IGMP snooping works

General query

IGMP report

Leave message

IGMP snooping proxying

Protocols and standards

Configuration restrictions and guidelines

IGMP snooping configuration task list

IGMP snooping configuration t as k list for VLANs

IGMP configuration task list for VSIs

Configuring basic IGMP snooping features

Enabling IGMP s nooping

Enabling IGMP snooping in IGMP-snooping view

Enabling IGMP snooping in VLAN or VSI view

Specifying an IGMP snooping version

Specifying an IGMP snooping version in IGMP-snooping view

Specifying an IGMP snooping version in VLAN or VSI view

Setting the maximum number of IGMP s noopi ng forwarding entries

Configuring static multicast MAC address entries

Configuration restrictions and guidelines

Configuring a static multicast MAC address entry in system view

Configuring a static multicast MAC address entry in interface view

Setting the IGMP las t member query interval

Configuration restrictions and guidelines

Setting the IGMP last member query interval globally

Setting the IGMP last member query interval in a VLAN or VSI

Configuring IGMP snooping port features

Setting aging tim er s for dynamic port s

Setting the aging timers for dynamic ports globally

Setting the aging timers for dynamic ports in a VLAN or VSI

Configuring static ports

Configuring a port as a simulated member host

Enabling fast-leave processin g

Configuration restrictions and guidelines

Enabling fast-leave processing globally

Enabling fast-leave processing on a port

Disabling a port from becoming a dynam ic router port

Configuring the IGMP snooping querier

Configuration prerequisites

Enabling the IGMP snooping querier

Configuration restrictions and guidelines

Configuration procedure

Configuring pa rameters for IGMP general queries and responses

Configuring parameters for IGMP general queries and responses globally

Configuring parameters for IGMP general queries and responses in a VLAN or VSI