HP FlexFabric 12900E Layer 3—IP Routing Configuration Guide

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HPE FlexFabric 12900E Switch Series

Layer 3—IP Routing Configuration Guide

P Software Document version: 6W101-20161201

art number: 5200-1237a

version: Release 2606 and later

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Configuring basic IP routing ··········································································· 1

Routing table ······················································································································································ 1 Dynamic routing protocols·································································································································· 2 Route preference ··············································································································································· 2 Load sharing ······················································································································································ 3 Route backup ····················································································································································· 3 Route recursion ·················································································································································· 3 Route redistribution ············································································································································ 3 Extension attribute redistribution ························································································································ 3 Setting the maximum lifetime for routes and labels in the RIB··········································································· 4 Setting the maximum lifetime for routes in the FIB ···························································································· 4 Configuring RIB NSR ········································································································································· 5

Configuring IPv4 RIB NSR ························································································································· 5 Configuring IPv6 RIB NSR ························································································································· 5

Configuring inter-protocol FRR ·························································································································· 6

Configuring IPv4 RIB inter-protocol FRR ··································································································· 6

Configuring IPv6 RIB inter-protocol FRR ··································································································· 6 Enabling the IPv4 enhanced ECMP mode ········································································································· 7 Displaying and maintaining a routing table ········································································································ 7

Configuring static routing ··············································································· 9

Configuring a static route ··································································································································· 9 Configuring BFD for static routes ····················································································································· 10

Bidirectional control mode ························································································································ 10

Single-hop echo mode ····························································································································· 11 Configuring static route FRR ···························································································································· 12

Configuration guidelines ··························································································································· 12

Configuring static route FRR by specifying a backup next hop································································ 12

Configuring static route FRR to automatically select a backup next hop ················································· 13

Enabling BFD echo packet mode for static route FRR ············································································ 13 Displaying and maintaining static routes ·········································································································· 13 Static route configuration examples ················································································································· 14

Basic static route configuration example ·································································································· 14

BFD for static routes configuration example (direct next hop) ································································· 15

BFD for static routes configuration example (indirect next hop) ······························································ 18

Static route FRR configuration example ·································································································· 20

Configuring a default route ··········································································· 23 Configuring RIP ··························································································· 24

RIP route entries ······································································································································ 24

Routing loop prevention ··························································································································· 24

RIP operation ··········································································································································· 24

RIP versions ············································································································································· 25

Protocols and standards ·························································································································· 25 RIP configuration task list································································································································· 25 Configuring basic RIP ······································································································································ 26

Enabling RIP ············································································································································ 26

Controlling RIP reception and advertisement on interfaces ····································································· 27

Configuring a RIP version ························································································································ 27 Configuring RIP route control ··························································································································· 28

Configuring an additional routing metric ··································································································· 28

Configuring RIPv2 route summarization ·································································································· 29

Disabling host route reception ·················································································································· 30

Advertising a default route ······················································································································· 30

Configuring received/redistributed route filtering······················································································ 30

Setting a preference for RIP ····················································································································· 31

Configuring RIP route redistribution ········································································································· 31 Tuning and optimizing RIP networks ··············································································································· 32

Configuration prerequisites ······················································································································ 32

Setting RIP timers ···································································································································· 32

Enabling split horizon and poison reverse ······························································································· 33

Setting the maximum number of RIP ECMP routes ················································································· 33

Enabling zero field check on incoming RIPv1 messages ········································································· 34

Enabling source IP address check on incoming RIP updates·································································· 34

Configuring RIPv2 message authentication ····························································································· 34

Setting the RIP triggered update interval ································································································· 35

Specifying a RIP neighbor ························································································································ 35

Configuring RIP network management ···································································································· 36

Configuring the RIP packet sending rate ································································································· 36

Setting the maximum length of RIP packets ···························································································· 37

Setting the DSCP value for outgoing RIP packets ··················································································· 37 Configuring RIP GR ········································································································································· 37 Enabling RIP NSR············································································································································ 38 Configuring BFD for RIP ·································································································································· 38

Configuring single-hop echo detection (for a directly connected RIP neighbor) ······································ 39

Configuring single-hop echo detection (for a specific destination) ··························································· 39

Configuring bidirectional control detection ······························································································· 40 Configuring RIP FRR ······································································································································· 40

Configuration restrictions and guidelines ································································································· 40

Configuration prerequisites ······················································································································ 41

Configuring RIP FRR ······························································································································· 41

Enabling BFD for RIP FRR ······················································································································ 41 Displaying and maintaining RIP ······················································································································· 41 RIP configuration examples ····························································································································· 42

Configuring basic RIP ······························································································································ 42

Configuring RIP route redistribution ········································································································· 45

Configuring an additional metric for a RIP interface················································································· 47

Configuring RIP to advertise a summary route ························································································ 48

Configuring RIP GR ································································································································· 51

Configuring RIP NSR ······························································································································· 52

Configuring BFD for RIP (single-hop echo detection for a directly connected neighbor) ························· 53

Configuring BFD for RIP (single hop echo detection for a specific destination) ······································· 56

Configuring BFD for RIP (bidirectional detection in BFD control packet mode) ······································· 58

Configuring RIP FRR ······························································································································· 61

Configuring OSPF························································································ 64

OSPF packets ·········································································································································· 64

LSA types ················································································································································· 64

OSPF areas ············································································································································· 65

Router types ············································································································································· 67

Route types ·············································································································································· 68

Route calculation ······································································································································ 68

OSPF network types ································································································································ 69

DR and BDR ············································································································································ 69

Protocols and standards ·························································································································· 70 OSPF configuration task list ····························································································································· 70 Enabling OSPF ················································································································································ 72

Configuration prerequisites ······················································································································ 72

Configuration guidelines ··························································································································· 73

Enabling OSPF on a network ··················································································································· 73

Enabling OSPF on an interface················································································································ 74 Configuring OSPF areas ·································································································································· 74

Configuring a stub area ···························································································································· 74

Configuring an NSSA area ······················································································································· 75

Configuring a virtual link ··························································································································· 75 Configuring OSPF network types ····················································································································· 76

Configuration prerequisites ······················································································································ 76

Configuring the broadcast network type for an interface·········································································· 76

Configuring the NBMA network type for an interface ··············································································· 76

Configuring the P2MP network type for an interface················································································ 77

Configuring the P2P network type for an interface··················································································· 78 Configuring OSPF route control ······················································································································· 78

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

Configuring OSPF route summarization ·································································································· 78

Configuring received OSPF route filtering ································································································ 79

Configuring Type-3 LSA filtering ·············································································································· 80

Setting an OSPF cost for an interface······································································································ 80

Setting the maximum number of ECMP routes ························································································ 81

Setting OSPF preference ························································································································· 81

Configuring discard routes for summary networks ··················································································· 81

Configuring OSPF route redistribution ····································································································· 82

Advertising a host route ··························································································································· 83

Excluding interfaces in an OSPF area from the base topology································································ 83 Tuning and optimizing OSPF networks ············································································································ 84

Configuration prerequisites ······················································································································ 84

Setting OSPF timers ································································································································ 84

Setting LSA transmission delay ··············································································································· 85

Setting SPF calculation interval ··············································································································· 85

Setting the LSA arrival interval ················································································································· 86

Setting the LSA generation interval·········································································································· 86

Disabling interfaces from receiving and sending OSPF packets ····························································· 87

Configuring stub routers ··························································································································· 87

Configuring OSPF authentication············································································································· 88

Adding the interface MTU into DD packets ······························································································ 89

Setting the DSCP value for outgoing OSPF packets ··············································································· 89

Setting the maximum number of external LSAs in LSDB········································································· 89

Setting OSPF exit overflow interval·········································································································· 89

Enabling compatibility with RFC 1583······································································································ 90

Logging neighbor state changes ·············································································································· 90

Configuring OSPF network management ································································································ 91

Setting the LSU transmit rate ··················································································································· 91

Setting the maximum length of OSPF packets that can be sent by an interface ····································· 92

Enabling OSPF ISPF ······························································································································· 92

Configuring prefix suppression ················································································································· 92

Configuring prefix prioritization ················································································································· 93

Configuring OSPF PIC ····························································································································· 94

Setting the number of OSPF logs ············································································································ 95

Filtering outbound LSAs on an interface ·································································································· 95

Filtering LSAs for the specified neighbor ································································································· 95

Configuring GTSM for OSPF ··················································································································· 96 Configuring OSPF GR······································································································································ 97

Configuring OSPF GR restarter ··············································································································· 97

Configuring OSPF GR helper ··················································································································· 98

Triggering OSPF GR ································································································································ 98 Configuring OSPF NSR ··································································································································· 99 Configuring BFD for OSPF······························································································································· 99

Configuring bidirectional control detection ······························································································· 99

Configuring single-hop echo detection ··································································································· 100 Configuring OSPF FRR·································································································································· 100

Configuration prerequisites ···················································································································· 100

Configuration guidelines ························································································································· 101

Configuration procedure ························································································································· 101 Advertising OSPF link state information to BGP ···························································································· 102 Displaying and maintaining OSPF ················································································································· 102 OSPF configuration examples ······················································································································· 104

Basic OSPF configuration example ······································································································· 104

OSPF route redistribution configuration example ·················································································· 106

OSPF route summarization configuration example ················································································ 108

iii

OSPF stub area configuration example ································································································· 111

OSPF NSSA area configuration example ······························································································ 113

OSPF DR election configuration example ······························································································ 115

OSPF virtual link configuration example ································································································ 119

OSPF GR configuration example ··········································································································· 121

OSPF NSR configuration example········································································································· 124

BFD for OSPF configuration example ···································································································· 126

OSPF FRR configuration example ········································································································· 129 Troubleshooting OSPF configuration ············································································································· 131

No OSPF neighbor relationship established ·························································································· 131

Incorrect routing information ·················································································································· 132

Configuring IS-IS ······················································································· 133

Terminology ··········································································································································· 133

IS-IS address format ······························································································································ 133

NET ························································································································································ 134

IS-IS area ··············································································································································· 135

IS-IS network types ································································································································ 136

IS-IS PDUs ············································································································································· 137

Protocols and standards ························································································································ 139 IS-IS configuration task list····························································································································· 139 Configuring basic IS-IS ·································································································································· 140

Configuration prerequisites ···················································································································· 140

Enabling IS-IS ········································································································································ 141

Setting the IS level and circuit level ······································································································· 141

Configuring P2P network type for an interface ······················································································· 141 Configuring IS-IS route control ······················································································································· 142

Configuration prerequisites ···················································································································· 142

Configuring IS-IS link cost ······················································································································ 142

Specifying a preference for IS-IS ··········································································································· 143

Configuring the maximum number of ECMP routes ··············································································· 144

Configuring IS-IS route summarization ·································································································· 144

Advertising a default route ····················································································································· 145

Configuring IS-IS route redistribution ····································································································· 145

Configuring IS-IS route filtering ·············································································································· 145

Configuring IS-IS route leaking ·············································································································· 146 Tuning and optimizing IS-IS networks ··········································································································· 147

Configuration prerequisites ···················································································································· 147

Specifying the interval for sending IS-IS hello packets ·········································································· 147

Specifying the IS-IS hello multiplier········································································································ 147

Specifying the interval for sending IS-IS CSNP packets ········································································ 148

Configuring a DIS priority for an interface ······························································································ 148

Disabling an interface from sending/receiving IS-IS packets ································································· 148

Enabling an interface to send small hello packets ················································································· 149

Configuring LSP parameters ·················································································································· 149

Controlling SPF calculation interval ······································································································· 151

Configuring convergence priorities for specific routes ··········································································· 152

Setting the LSDB overload bit ················································································································ 152

Configuring the ATT bit ·························································································································· 153

Configuring the tag value for an interface ······························································································ 153

Configuring system ID to host name mappings ····················································································· 154

Enabling the logging of neighbor state changes ···················································································· 155

Enabling IS-IS ISPF ······························································································································· 155

Enabling prefix suppression ··················································································································· 155

Configuring IS-IS network management ································································································ 156

Configuring IS-IS PIC ····························································································································· 157 Enhancing IS-IS network security ·················································································································· 158

Configuration prerequisites ···················································································································· 158

Configuring neighbor relationship authentication ··················································································· 158

Configuring area authentication ············································································································· 158

Configuring routing domain authentication····························································································· 159

Configuring IS-IS GR ····································································································································· 159 Configuring IS-IS NSR ··································································································································· 160 Configuring BFD for IS-IS ······························································································································ 161 Configuring IS-IS FRR ··································································································································· 161

Configuration prerequisites ···················································································································· 162

Configuration guidelines ························································································································· 162

Configuration procedure ························································································································· 162 Displaying and maintaining IS-IS ··················································································································· 163 IS-IS configuration examples ························································································································· 165

Basic IS-IS configuration example ········································································································· 165

DIS election configuration example········································································································ 169

IS-IS route redistribution configuration example ···················································································· 173

IS-IS authentication configuration example···························································································· 177

IS-IS GR configuration example············································································································· 180

IS-IS NSR configuration example ·········································································································· 181

BFD for IS-IS configuration example ······································································································ 184

IS-IS FRR configuration example··········································································································· 187

Configuring BGP ························································································ 191

BGP speaker and BGP peer ·················································································································· 191

BGP message types ······························································································································ 191

BGP path attributes ································································································································ 191

BGP route selection ······························································································································· 195

BGP route advertisement rules ·············································································································· 195

BGP load balancing ······························································································································· 196

Settlements for problems in large-scale BGP networks ········································································· 197

MP-BGP ················································································································································· 200

BGP multi-instance ································································································································ 201

BGP configuration views ························································································································ 201

Protocols and standards ························································································································ 203 BGP configuration task list ····························································································································· 203 Configuring basic BGP ··································································································································· 206

Enabling BGP ········································································································································· 206

Configuring a BGP peer ························································································································· 207

Configuring dynamic BGP peers ············································································································ 209

Configuring a BGP peer group ··············································································································· 211

Specifying the source address of TCP connections ··············································································· 220 Generating BGP routes ·································································································································· 221

Injecting a local network ························································································································· 221

Redistributing IGP routes ······················································································································· 223 Controlling route distribution and reception ··································································································· 224

Configuring BGP route summarization ··································································································· 224

Advertising optimal routes in the IP routing table ··················································································· 227

Advertising a default route to a peer or peer group················································································ 228

Limiting routes received from a peer or peer group ··············································································· 230

Configuring BGP route filtering policies ································································································· 231

Configuring BGP route update delay ····································································································· 237

Configuring BGP route dampening ········································································································ 238 Controlling BGP path selection ······················································································································ 239

Setting a preferred value for routes received ························································································· 239

Configuring preferences for BGP routes ································································································ 241

Configuring the default local preference ································································································ 242

Configuring the MED attribute ················································································································ 244

Configuring the NEXT_HOP attribute ···································································································· 248

Configuring the AS_PATH attribute ······································································································· 250

Ignoring IGP metrics during optimal route selection ·············································································· 255

Configuring the SoO attribute ················································································································· 256 Tuning and optimizing BGP networks ············································································································ 258

Configuring the keepalive interval and hold time ··················································································· 258

Configuring the interval for sending updates for the same route ··························································· 259

Enabling BGP to establish an EBGP session over multiple hops ·························································· 260

Enabling immediate re-establishment of direct EBGP connections upon link failure ····························· 261

Enabling 4-byte AS number suppression ······························································································· 262

Enabling MD5 authentication for BGP peers ························································································· 263

Enabling keychain authentication for BGP peers ··················································································· 264

Configuring BGP load balancing ············································································································ 265

Disabling BGP to establish a session to a peer or peer group ······························································· 266

Configuring GTSM for BGP ···················································································································· 267

Configuring BGP soft-reset ···················································································································· 268

Protecting an EBGP peer when memory usage reaches level 2 threshold ··········································· 274

Configuring an update delay for local MPLS labels ··············································································· 275

Flushing the suboptimal BGP route to the RIB ······················································································ 276

Setting a DSCP value for outgoing BGP packets ·················································································· 276

Enabling per-prefix label allocation ········································································································ 277

Disabling optimal route selection for labeled routes without tunnel information ····································· 277 Configuring a large-scale BGP network ········································································································· 278

Configuring BGP community ·················································································································· 278

Configuring BGP route reflection ··········································································································· 280

Configuring a BGP confederation ·········································································································· 282 Configuring BGP GR ······································································································································ 283 Configuring BGP NSR···································································································································· 284 Enabling SNMP notifications for BGP ············································································································ 285 Enabling logging for session state changes ··································································································· 285 Enabling logging for BGP route flapping ········································································································ 286 Configuring BFD for BGP ······························································································································· 288 Configuring BGP FRR ···································································································································· 289 Configuring 6PE ············································································································································· 292

Configuring basic 6PE ···························································································································· 292

Configuring optional 6PE capabilities····································································································· 293 Configuring BGP LS ······································································································································· 295

Configuring basic BGP LS ····················································································································· 295

Configuring BGP LS route reflection ······································································································ 295

Specifying an AS number and a router ID for BGP LS messages ························································· 296 Displaying and maintaining BGP···················································································································· 296

Displaying BGP ······································································································································ 296

Resetting BGP sessions ························································································································ 299

Clearing BGP information ······················································································································ 299 IPv4 BGP configuration examples ················································································································· 300

Basic BGP configuration example·········································································································· 300

BGP and IGP route redistribution configuration example ······································································ 304

BGP route summarization configuration example ·················································································· 307

BGP load balancing configuration example ··························································································· 310

BGP community configuration example ································································································· 313

BGP route reflector configuration example ···························································································· 316

BGP confederation configuration example····························································································· 318

BGP path selection configuration example ···························································································· 322

BGP GR configuration example ············································································································· 325

BFD for BGP configuration example ······································································································ 326

BGP FRR configuration example ··········································································································· 330

Multicast BGP configuration example ···································································································· 334

Dynamic BGP peer configuration example ···························································································· 337

BGP LS configuration example ·············································································································· 339 IPv6 BGP configuration examples ················································································································· 341

IPv6 BGP basic configuration example ·································································································· 341

IPv6 BGP route reflector configuration example ···················································································· 344

6PE configuration example ···················································································································· 347

BFD for IPv6 BGP configuration example ······························································································ 350

IPv6 BGP FRR configuration example ··································································································· 353 Troubleshooting BGP ····································································································································· 357

Symptom ················································································································································ 357

Analysis ·················································································································································· 357

Solution ·················································································································································· 357

Configuring PBR ························································································ 358

Policy ······················································································································································ 358

PBR and Track ······································································································································· 359 PBR configuration task list ····························································································································· 359 Configuring a policy········································································································································ 360

Creating a node ······································································································································ 360

Setting match criteria for a node ············································································································ 360

Configuring actions for a node ··············································································································· 361 Specifying a policy for PBR ···························································································································· 361

Specifying a policy for local PBR ··········································································································· 361

Specifying a policy for interface PBR ····································································································· 362

Specifying a policy for outbound PBR on a VXLAN tunnel interface ····················································· 362 Displaying and maintaining PBR ···················································································································· 363 PBR configuration examples ·························································································································· 363

Packet type-based local PBR configuration example ············································································ 363

Packet type-based interface PBR configuration example ······································································ 365

Configuring IPv6 static routing ··································································· 367

Configuring an IPv6 static route ····················································································································· 367 Configuring BFD for IPv6 static routes ··········································································································· 367

Bidirectional control mode ······················································································································ 368

Single-hop echo mode ··························································································································· 368 Displaying and maintaining IPv6 static routes································································································ 369 IPv6 static routing configuration examples ···································································································· 369

Basic IPv6 static route configuration example ······················································································· 369

BFD for IPv6 static routes configuration example (direct next hop) ······················································· 371

BFD for IPv6 static routes configuration example (indirect next hop) ···················································· 374

Configuring an IPv6 default route······························································· 377 Configuring RIPng ····················································································· 378

RIPng route entries ································································································································ 378

RIPng packets ········································································································································ 378

Protocols and standards ························································································································ 379 RIPng configuration task list··························································································································· 379 Configuring basic RIPng ································································································································ 379 Configuring RIPng route control ····················································································································· 380

Configuring an additional routing metric ································································································· 380

Configuring RIPng route summarization ································································································ 380

Advertising a default route ····················································································································· 381

Configuring received/redistributed route filtering···················································································· 381

Setting a preference for RIPng ··············································································································· 381

Configuring RIPng route redistribution ··································································································· 382 Tuning and optimizing the RIPng network ····································································································· 382

Setting RIPng timers ······························································································································ 382

Configuring split horizon and poison reverse ························································································· 383

Configuring zero field check on RIPng packets ····················································································· 383

Setting the maximum number of ECMP routes ······················································································ 384

Configuring the RIPng packet sending rate ··························································································· 384

Setting the interval for sending triggered updates ·················································································· 385 Configuring RIPng GR ··································································································································· 385 Configuring RIPng NSR ································································································································· 386 Configuring RIPng FRR ································································································································· 386

Configuration restrictions and guidelines ······························································································· 387

Configuration prerequisites ···················································································································· 387

Configuring RIPng FRR ························································································································· 387

Enabling BFD for RIPng FRR ················································································································ 387 Displaying and maintaining RIPng ················································································································· 388 RIPng configuration examples ······················································································································· 388

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Basic RIPng configuration example ······································································································· 388

RIPng route redistribution configuration example ·················································································· 391

RIPng GR configuration example··········································································································· 393

RIPng NSR configuration example ········································································································ 394

Configuring RIPng FRR ························································································································· 396

Configuring OSPFv3 ·················································································· 399

OSPFv3 packets ···································································································································· 399

OSPFv3 LSA types ································································································································ 399

Protocols and standards ························································································································ 400 OSPFv3 configuration task list ······················································································································· 400 Enabling OSPFv3··········································································································································· 401 Configuring OSPFv3 area parameters ··········································································································· 402

Configuration prerequisites ···················································································································· 402

Configuring a stub area ·························································································································· 402

Configuring an NSSA area ····················································································································· 402

Configuring an OSPFv3 virtual link ········································································································ 403 Configuring OSPFv3 network types ··············································································································· 403

Configuration prerequisites ···················································································································· 404

Configuring the OSPFv3 network type for an interface ·········································································· 404

Configuring an NBMA or P2MP neighbor ······························································································ 404 Configuring OSPFv3 route control ················································································································· 405

Configuration prerequisites ···················································································································· 405

Configuring OSPFv3 route summarization ····························································································· 405

Configuring OSPFv3 received route filtering ·························································································· 406

Configuring Inter-Area-Prefix LSA filtering ····························································································· 406

Setting an OSPFv3 cost for an interface ································································································ 406

Setting the maximum number of OSPFv3 ECMP routes ······································································· 407

Setting a preference for OSPFv3 ··········································································································· 407

Configuring OSPFv3 route redistribution ······························································································· 408 Tuning and optimizing OSPFv3 networks ······································································································ 409

Configuration prerequisites ···················································································································· 409

Setting OSPFv3 timers ··························································································································· 409

Setting LSA transmission delay ············································································································· 410

Setting SPF calculation interval ············································································································· 410

Setting the LSA generation interval········································································································ 410

Setting a DR priority for an interface ······································································································ 411

Ignoring MTU check for DD packets ······································································································ 411

Disabling interfaces from receiving and sending OSPFv3 packets ························································ 411

Enabling logging for neighbor state changes ························································································· 412

Configuring OSPFv3 network management··························································································· 412

Setting the LSU transmit rate ················································································································· 413

Configuring stub routers ························································································································· 413

Configuring prefix suppression ··············································································································· 414

Setting the maximum number of OSPFv3 logs ······················································································ 415

Configuring OSPFv3 authentication ······································································································· 415 Configuring OSPFv3 GR ································································································································ 416

Configuring GR restarter ························································································································ 416

Configuring GR helper ··························································································································· 417

Triggering OSPFv3 GR ·························································································································· 417 Configuring OSPFv3 NSR······························································································································ 417 Configuring BFD for OSPFv3 ························································································································· 418 Configuring OSPFv3 FRR ······························································································································ 418

Configuration prerequisites ···················································································································· 419

Configuration guidelines ························································································································· 419

Configuration procedure ························································································································· 419 Displaying and maintaining OSPFv3·············································································································· 421 OSPFv3 configuration examples···················································································································· 422

OSPFv3 stub area configuration example ····························································································· 422

OSPFv3 NSSA area configuration example ·························································································· 426

OSPFv3 DR election configuration example ·························································································· 428

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OSPFv3 route redistribution configuration example··············································································· 431

OSPFv3 route summarization configuration example ············································································ 434

OSPFv3 GR configuration example ······································································································· 438

OSPFv3 NSR configuration example ····································································································· 439

BFD for OSPFv3 configuration example ································································································ 440

OSPFv3 FRR configuration example ····································································································· 443

Configuring IPv6 IS-IS ··············································································· 446

Overview ························································································································································ 446 Configuring basic IPv6 IS-IS ·························································································································· 446 Configuring IPv6 IS-IS route control ·············································································································· 447

Configuring IPv6 IS-IS link cost·············································································································· 448 Tuning and optimizing IPv6 IS-IS networks ··································································································· 449

Configuration prerequisites ···················································································································· 449

Assigning a convergence priority to IPv6 IS-IS routes ··········································································· 449

Setting the LSDB overload bit ················································································································ 450

Configuring a tag value on an interface ································································································· 450

Controlling SPF calculation interval ······································································································· 450

Enabling IPv6 IS-IS ISPF ······················································································································· 451

Enabling prefix suppression ··················································································································· 451 Configuring BFD for IPv6 IS-IS ······················································································································ 451 Configuring IPv6 IS-IS FRR ··························································································································· 452

Configuration prerequisites ···················································································································· 452

Configuration procedure ························································································································· 453 Enabling IPv6 IS-IS MTR ······························································································································· 454 Displaying and maintaining IPv6 IS-IS ··········································································································· 455 IPv6 IS-IS configuration examples ················································································································· 455

IPv6 IS-IS basic configuration example ································································································· 455

BFD for IPv6 IS-IS configuration example ····························································································· 460

IPv6 IS-IS FRR configuration example ·································································································· 462

Configuring IPv6 PBR ················································································ 466

PBR and Track ······································································································································· 467 IPv6 PBR configuration task list ····················································································································· 467 Configuring an IPv6 policy ····························································································································· 467

Creating an IPv6 node ··························································································································· 467

Setting match criteria for an IPv6 node ·································································································· 468

Configuring actions for an IPv6 node ····································································································· 468 Configuring IPv6 PBR ···································································································································· 469

Configuring IPv6 local PBR ···················································································································· 469

Configuring IPv6 interface PBR ············································································································· 469 Displaying and maintaining IPv6 PBR············································································································ 470 IPv6 PBR configuration examples·················································································································· 470

Packet type-based IPv6 local PBR configuration example ···································································· 470

Packet type-based IPv6 interface PBR configuration example ······························································ 472

Configuring routing policies ········································································ 475

Filters ····················································································································································· 475

Routing policy ········································································································································· 475 Configuring filters ··········································································································································· 476

Configuration prerequisites ···················································································································· 476

Configuring an IP prefix list ···················································································································· 476

Configuring an AS path list ····················································································································· 477

Configuring a community list ·················································································································· 477

Configuring an extended community list ································································································ 477 Configuring a routing policy···························································································································· 478

Configuration prerequisites ···················································································································· 478

Creating a routing policy ························································································································ 478

Configuring if-match clauses ·················································································································· 478

Configuring apply clauses ······················································································································ 480

Configuring the continue clause ············································································································· 481 Displaying and maintaining the routing policy ································································································ 482 Routing policy configuration examples ·········································································································· 482

Routing policy configuration example for IPv4 route redistribution ························································ 482

Routing policy configuration example for IPv6 route redistribution ························································ 485

Document conventions and icons ······························································ 488

Conventions ··················································································································································· 488 Network topology icons ·································································································································· 489

Support and other resources ····································································· 490

Accessing Hewlett Packard Enterprise Support····························································································· 490 Accessing updates ········································································································································· 490

Websites ················································································································································ 490

Customer self repair ······························································································································· 491

Remote support ······································································································································ 491

Documentation feedback ······················································································································· 491

Index ·········································································································· 492

Configuring basic IP routing

Criterion

Routing table

A RIB contains the global routing information and related information, including route recursion, route redistribution, and ro ute extension information. The r outer selects optimal routes f rom the routing table and puts them into the FIB table. It uses the FIB table to forward packets. For more information about the FIB table, see Layer 3—IP Services Configuration Guide.

Table 1 categorizes routes by different criteria.

Table 1 Route categories

• Network route—

Destination

bits.

• Host route—The destination is a host. The subnet mask is 32 bits.

destination is directly connected

Origin

• Direct route—The destination is directly connected.

• Indirect route—The destination is indirectly connected.

• Direct route—A direct route is discovered by the data link protocol on an

interface, and is also called an interface route.

• Static route—A static route is manually configured by an administrator.

• Dynamic route—A dynamic route is dynamically discovered by a routing

protocol.

To view brief information about a routing table, use the display ip routing-table command.

<Sysname> display ip routing-table

Destinations : 9 Routes : 9

Destination/Mask Proto Pre Cost NextHop Interface

0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

3.3.3.3/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0 ...

A route entry includes the following key items:

Destination—IP address of the destination host or network. Mask—Mask length of the IP address. Proto—Protocol that installed the route. Pre—Preference of the route. Among routes to the same destination, the route with the highest

preference is optimal.

•

Criterion

Dynamic routing protocols

Static routes work well in small, stable networks. They are easy to configure and require fewer system resources. However, in networks where topology changes occur frequently, a typical practice is to configure a dynamic routing protocol. Compared with static routing, a dynamic routing protocol is complicated to configure, requires more router resources, and consumes more network resources.

Dynamic routing protocols dynamically collect and report reachability information to adapt to topology changes. They are suitable for large networks.

Dynamic routing protocols can be classified by different criteria, as shown in Table 2.

Table 2 Categories of dynamic routing protocols

Operation scope

Routing algorithm

Destination address type

IP version

• IGPs—Work within an AS. Examples includ e RIP, OSPF, and IS-IS.

• EGPs—Work between ASs. The most popular EGP is BGP.

• Distance-vector protocols—Examples include

considered a path-vector protocol.

• Link-state protocols—Examples include OSPF and IS-IS.

• Unicast routing protocols—Examples include RIP, OSPF, BGP, and IS-IS.

• Multicast routing protocols—Examples include PIM-SM and PIM-DM.

• IPv4 routing protocols—Examples include RIP, OSPF, BGP, and IS-IS.

• IPv6 routing protocols—Examples include RIPng, OSPFv3, IPv6 BGP, and

IPv6 IS-IS.

An AS refers to a group of routers that use the sam e routing policy and work under the same administration.

Route preference

Routing protocols, includ in g stat ic and direc t r out ing, eac h b y defau lt have a preference. If they find multiple routes to the sam e dest ination, the router selec ts the r oute with the hig hest pref erence as the optimal route.

The preference of a direct route is always 0 and cannot be changed. Y ou can configure a preference for each static route and each dynamic routing protocol. The following table lists the route types and default preferences. The smaller the value, the higher the preference.

Table 3 Route types and default route preferences

Direct route 0 Multicast static route 1 OSPF 10 IS-IS 15 Unicast static route 60

Route type

Preference

RIP 100 OSPF ASE 150 OSPF NSSA 150 IBGP 255 EBGP 255 Unknown (route from an untrusted source) 256

Load sharing

A routing protocol might find multiple optimal equal-cost routes to the same destination. You can use these routes to implement equal-cost multi-path (ECMP) load sharing.

Static routing, IPv6 static routing, RIP, RIPng, OSPF, OSPFv3, BGP, IP v6 B GP, IS-IS, and IPv6 IS-IS support ECMP load sharing.

Route backup

Route backup can im prove network availability. Among m ultiple rout es to the s ame destin ation, the route with the highest priority is the prim ary route and others are secondary routes.

The router forwards m atching p ackets through the prim ary route. W hen the primar y route fails, the route with the highest preference among the secondary routes is selected to forward packets. When the primary route recovers, the router uses it to forward packets.

Route recursion

To use a BGP, s tatic , or R I P route that has an ind irec tl y co nnec t ed nex t ho p, a r o uter must perform route recursion to find the output interface to reach the next hop.

Link-state routing pro tocols, such as O SPF and IS-IS, do not need route rec ursion, because th ey obtain directly connected next hops through route calculation.

The RIB records and sa ves route recursion informati on, including brief information abo ut related routes, recursive paths, and recur sion dep th.

Route redistribution

Route redistribution enables routing protocols to learn routing information from each other. A dynamic routing pr otocol can redistribute routes from other routing protocols, including direct and static routing. For more inform ation, see the respective c hapters on those ro uting protocols in this configuration guide.

The RIB records redistribution relationships of routing protocols.

Extension attribute redistribution

Extension attribute redistribution enables routi ng protocols to learn route extension attri butes from each other, including BGP extended comm unity attributes , OSPF area IDs , route types, and rout er IDs.

The RIB records extended attributes of each routing protocol and redistribution relationships of

Step

Command

Remarks

rib

y default, no RIB IPv4

y default, the maximum

Step

Command

Remarks

y default, no RIB IPv6

y default, the maximum

Step

Command

Remarks

y default, no RIB IPv4

different routing protocol extended attributes.

Setting the maximum lifetime for routes and labels in the RIB

Perform this task to prevent rout es of a certain protocol from being aged out due to slo w protocol convergence resulting from a large number of route entries or long GR period.

The configuration takes effect at the next protocol or RIB process switchover. To set the maximum lifetime for routes and labels in the RIB (IPv4):

1. Enter system view.

2. Enter RIB view.

3. Create the RIB IPv4 address

family and enter its view.

4. Set the maximum lifetime for IPv4 routes and labels in the RIB.

To set the maximum route lifetime for routes and labels in the RIB (IPv6):

1. Enter system view.

2. Enter RIB view.

3. Create the RIB IPv6 address

family and enter its view.

4. Set the maximum lifetime for IPv6 routes and labels in the RIB.

system-view

address-family ipv4

protocol

instance-name ]

system-view rib

address-family ipv6

protocol

instance-name ]

protocol [

lifetime

protocol [

lifetime

instance

seconds

instance

seconds

N/A N/A B

address family exists. B

lifetime for routes and labels in the RIB is 480 seconds.

N/A N/A B

address family exists. B

lifetime for routes and labels in the RIB is 480 seconds.

Setting the maximum lifetime for routes in the FIB

When GR or NSR is disabled, FIB entries m ust be ret ained for s ome tim e after a protoco l proces s switchover or RIB proces s switcho ver. When GR or NSR is enab led, FIB entri es m ust be removed immediately after a protocol or RIB pr oc ess switchover to avoi d routing issues. Pe rf orm this task to meet such requirements.

To set the maximum lifetime for routes in the FIB (IPv4):

1. Enter system view.

2. Enter RIB view.

3. Create the RIB IPv4 address

family and enter its view.

system-view rib

address-family ipv4

N/A N/A B

address family exists.

Step

Command

Remarks

4. Set the maximum lifetime for

y default, the maximum

lifetime for routes in the FIB

Step

Command

Remarks

y default, no RIB IPv6

y default, the maximum

lifetime for routes in the FIB

IMPORTANT:

Use this feature with protocol GR or NSR to avoid route timeouts and traffic interruption.

Step

Command

Remarks

By default, no RIB IPv4

By default, RIB NSR is

Step

Command

Remarks

RIB IPv6

IPv4 routes in the FIB.

To set the maximum lifetime for routes in the FIB (IPv6):

fib lifetime

seconds

B is 600 seconds.

1. Enter system view.

2. Enter RIB view.

3. Create the RIB IPv6 address

family and enter its view.

4. Set the maximum lifetime for IPv6 routes in the FIB.

system-view rib

address-family ipv6

fib lifetime

Configuring RIB NSR

When an active/standby switchover occurs, nonstop routing (NSR) backs up routing information from the active process to the standby process to a void routing flapping and ensure forwarding continuity.

RIB NSR provides faster route convergence than protocol NSR during an active/standby switchover.

Configuring IP v4 RIB NSR

seconds

N/A N/A B

address family exists. B

is 600 seconds.

1. Enter system view.

2. Enter RIB view.

3. Create the RIB IPv4 address

family and enter its view.

4. Enable IPv4 RIB NSR.

system-view rib

address-family ipv4

non-stop-routing

Configuring IP v6 RIB NSR

1. Enter system view.

2. Enter RIB view.

3. Create the RIB IPv6 address

family and enter its view.

system-view rib

address-family ipv6

N/A N/A

address family exists.

disabled.

N/A N/A By default, no

address family exists.

Step

Command

Remarks

4. Enable IPv6 RIB NSR.

By default, RIB NSR is

CAUTION:

This feature faulty route, which might cause loops.

Step

Command

Remarks

By default, no RIB IPv4

Enable IPv4 RIB

protocol FRR

is enabled for the public

Step

Command

Remarks

By default, no RIB IPv6

Enable IPv6 RIB

protocol FRR

is enabled for the public

non-stop-routing

Configuring inter-protocol FRR

disabled.

uses the next hop of a route from a different protocol as the backup next hop for the

Inter-protocol fast reroute (FRR) enables fast rerouting between routes of different protocols. A backup next hop is automatically selected to reduce the service interruption time caused by unreachable next hops. W hen the next hop of the prim ary link fails, the traffic is redirected to the backup next hop.

Among the routes to the same destination in the RIB, a router adds the route with the highest preference to the FIB tab le. For example, if a static route and an O SPF route in the RI B have the same destination, the router adds the OSPF ro ute to the FIB ta ble by default. The next hop of the static route is selected as the backup next hop for the OSPF route. When the next hop of the OSPF route is unreachable, the backup next hop is used.

Configuring IP v4 RIB inter-protoc ol FRR

1. Enter system view.

2. Enter RIB view.

3. Create the RIB IPv4 address

family and enter its view.

system-view rib

address-family ipv4

N/A N/A

address family exists.

inter-protocol FRR.

inter-protocol fast-reroute

vpn-instance

[

vpn-instance-name ]

Configuring IP v6 RIB inter-protoc ol FRR

1. Enter system view.

2. Enter RIB view.

3. Create the RIB IPv6 address

family and enter its view.

inter-protocol FRR.

system-view rib

address-family ipv6

inter-protocol fast-reroute

vpn-instance

[

vpn-instance-name ]

By default, inter-protocol FRR is disabled.

If you do not specify a VPN instance, inter-

network.

N/A N/A

address family exists. By default, inter-protocol

FRR is disabled. If you do not specify a VPN

instance, internetwork.

Step

Command

Remarks

Enable the IPv4 enhanced

By default, the IPv4 enhanced ECMP mode is

Task

Command

information about routes

Display information about routes

routing table

Display next hop information in the

Enabling the IPv4 enhanced ECMP mode

When one or multiple ECMP routes fail, the default ECMP mode enables the device to reallocate all traffic to the remaining routes.

The IPv4 enhanced ECMP mode enables the device to reallocate only the traffic of the failed routes to the remaining routes, which ensures forwarding continuity.

This configuration takes effect at reboot. Make sure the reboot does not impact your network. To enable the IPv4 enhanced ECMP mode:

1. Enter system view.

ECMP mode.

system-view

ecmp mode enhanced

N/A

disabled.

Displaying and maintaining a routing table

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

Display the IPv4 ECMP mode.

Display routing table information.

Display information about routes permitted by an IPv4 basic ACL.

Display information about routes to a specific destination address.

Display information about routes to a range of destination addresses.

Display permitted by an IP prefix list.

display ecmp mode display ip routing-table

verbose ]

[

display ip routing-table [ vpn-instance

ipv4-acl-number [

display ip routing-table

ip-address [ mask-length | mask ] [

display ip routing-table

ip-address1 to ip-address2 [

display ip routing-table [ vpn-instance prefix-list

prefix-list-name [

verbose ]

vpn-instance

[

vpn-instance

[

longer-match

vpn-instance

[

verbose ]

vpn-instance-name ]

verbose ]

] [

acl

installed by a protocol.

Display IPv4 route statistics.

Display brief IPv4 information.

Display route attribute information in the RIB.

Display RIB GR state information.

RIB. Display next hop informatio n for direct

routes.

display ip routing-table protocol

display ip routing-table statistics

display ip routing-table summary

display rib attribute

display rib graceful-restart display rib nib

display rib nib protocol

display route-direct nib

protocol [

self-originated

[

inactive

[

[ attribute-id ]

protocol [

[ nib-id ] [

vpn-instance

verbose ]

vpn-instance

] [ nib-id ] [

verbose ]

vpn-instance-name ]

verbose

]

Task

Command

Clear IPv4 route statistics.

isplay information about routes to a

information about routes

routing table

attribute information in

Display IPv6 RIB GR state

Display next hop information in the

reset ip routing-table statistics protocol [ vpn-instance

vpn-instance-name ] { protocol |

all }

Display IPv6 routing tab le infor mation.

Display information about rout es to an IPv6 destination address.

Display information about routes permitted by an IPv6 basic ACL.

D range of IPv6 destination addresses.

Display permitted by an IPv6 prefix list.

Display installed by an IPv6 protocol.

Display IPv6 route statistics.

Display brief IPv6 information.

Display route the IPv6 RIB.

information.

IPv6 RIB.

display ipv6 routing-table [ vpn-instance

verbose ]

[

display ipv6 routing-table [ vpn-instance

ipv6-address [ prefix-length ] [

display ipv6 routing-table [ vpn-instance acl

ipv6-acl-number [

display ipv6 routing-table [ vpn-instance

ipv6-address1 to ipv6-address2 [

display ipv6 routing-table prefix-list

display ipv6 routing-table [ vpn-instance protocol

display ipv6 routing-table [ vpn-instance statistics

display ipv6 routing-table summary

display ipv6 rib attribute

display ipv6 rib graceful-restart

display ipv6 rib nib display ipv6 rib nib protocol

prefix-list-name [

protocol [

verbose ]

inactive | verbose ]

self-originated

[

longer-match

verbose ]

vpn-instance

[

verbose ]

vpn-instance

[

[ attribute-id ]

protocol [

] [ nib-id ] [

verbose ]

vpn-instance-name ]

verbose ]

] [

vpn-instance-name ]

verbose

]

Display next hop information for IPv6 direct routes.

Clear IPv6 route statistics.

display ipv6 route-direct nib

reset ipv6 routing-table statistics protocol

vpn-instance-name ] { protocol |

[ nib-id ] [

all }

verbose ]

vpn-instance

[

•

Step

Command

Remarks

system-view

static route group

(Optional.) Add a the static route

By default, no static route

figure a static

] |

Configuring static routing

Static routes are m anuall y conf igured. If a net work 's topology is sim ple, you only nee d to co nfigure static routes for the network to work correctly.

Static routes cannot ada pt t o net wor k topology changes. If a fault or a topological change oc c urs in the network, the network administrator must modify the static routes manually.

Configuring a static route

Before you configure a static route, complete the following tasks:

Configure the physical parameters for related interfaces. Configure the link-layer attributes for related interfaces. Configure the IP addresses for related interfaces.

You can associate Track with a static route to m onitor the reachabil ity of the next hops. For m ore information about Track, see High Availability Configuration Guide.

To configure a static route:

1. Enter system view.

2. (Optional.) Create a

and enter its view.

static route prefix to group.

4. (Optional.) Return to system view.

5. Con route.

ip route-static-group

prefix

dest-address { mask-length | mask }

quit

• Method 1: ip route-static { dest-address { mask-length

| mask } | group group-name } { interface-type interface-number [ next-hop-address ] | next-hop-address [ track track-entry-number ] | vpn-instance d-vpn-instance-name next-hop-address [ track track-entry-number ] } [ permanent ] [ preference preference ] [ tag tag-value ] [ description text ]

• Method 2: ip route-static vpn-instance s-vpn-instance-name { dest-address { mask-length | mask } | group group-name } { interface-type interface-number [ next-hop-address ] | next-hop-address [ public ] [ track track-entry-number

vpn-instance d-vpn-instance-name next-hop-address [ track track-entry-number ] } [ permanent ]

[ preference preference ] [ tag tag-value ] [ description text ]

group-name

N/A By default, no static route

group is configured.

prefix is added to the static route group.

N/A

By default, no static route is configured.

Step

Command

Remarks

Configure the default preference

static routes,

To delete one static route,

undo ip

IMPORTANT:

Enabling BFD for a flapping route could worsen the situation.

•

Step

Command

Remarks

Configure BFD

Step

Command

Remarks

6. (Optional.)

ip route-static default-preference

for static routes.

7. (Optional.) Delete all including the default

route.

default-preference

delete [ vpn-instance static-routes all

vpn-instance-name ]

Configuring BFD for static routes

The default setting is 60.

use the

route-static

command.

BFD provides a general-purpose, standard, medium-, and protocol-independent fast failure detection mechanis m. It can uniformly and quickly detec t th e failures of the b id ire c tiona l f orwarding paths between two routers for protocols, such as routing protocols and MPLS.

For more information about BFD, see High Availability Configuration Guide.

Bidirectional c ontrol mode

To use BFD bidirectional control detection between two devices, enable BFD control mode for each device's static route destined to the peer.

To configure a static route and enable BFD control mode, use one of the following methods:

Specify an output interface and a direct next hop. Specify an indirect next hop and a specific BFD packet source address for the static route.

To configure BFD control mode for a static route (direct next hop):

1. Enter system view.

control mode for a static route.

To configure BFD control mode for a static route (indirect next hop):

system-view

• Method 1:

ip route-static dest-address { mask-length | mask } interface-type interface-number next-hop-address bfd control-packet

[ preference preference ] [ tag tag-value ] [ description text ]

• Method 2:

ip route-static vpn-instance s-vpn-instance-name dest-address

{ mask-length | mask } interface-type interface-number next-hop-address bfd control-packet [ preference preference ] [ tag tag-value ] [ description text ]

N/A

By default, BFD control mode for a static route is not configured.

1. Enter system view.

system-view

N/A

Step

Command

Remarks

Configure BFD

By default, BFD control

IMPORTANT:

Do not use BFD for a static route with the output interface in spoofing state.

Step

Command

Remarks

Configure the source address of

, the source

Availability Command

for a static

for a static route is not

• Method 1:

control mode for a static route.

• Method 2:

Single-hop echo mode

With BFD echo mode enabled for a static route, the output interface sends BFD echo packets to the destination device, which loops the packets back to test the link reachability.

ip route-static dest-address { mask-length | mask } { next-hop-address bfd control-packet bfd-source ip-address | vpn-instance d-vpn-instance-name next-hop-address bfd

control-packet bfd-source ip-address } [ preference preference ] [ tag tag-value ] [ description text ]

ip route-static vpn-instance s-vpn-instance-name dest-address { mask-length | mask } { next-hop-address bfd control-packet bfd-source ip-address | vpn-instance d-vpn-instance-name next-hop-address bfd control-packet bfd-source ip-address } [ preference

preference ] [ tag tag-value ] [ description text ]

mode for a static route is not configured.

To configure BFD echo mode for a static route:

1. Enter system view.

echo packets.

3. Configure BFD echo mode route.

system-view

bfd echo-source-ip

• Method 1:

ip route-static dest-address { mask-length | mask } interface-type interface-number next-hop-address bfd echo-packet

[ preference preference ] [ tag tag-value ] [ description text ]

• Method 2: ip route-static vpn-instance s-vpn-instance-name dest-address { mask-length | mask } interface-type

interface-number next-hop-address bfd echo-packet [ preference preference ] [ tag

tag-value ] [ description text ]

ip-address

N/A By default

address of echo packets is not configured.

For more information a bout this command, see High

Reference.

By default, BFD echo mode configured.

•

Step

Command

Remarks

Configure static route

] ] ]

tag

description

By default, static route FRR

Router A

Router B Router E

Backup nexthop:

Router C

Nexthop:

Router D

Configuring static route FRR

A link or router failure on a path can cause packet loss and even routing loop. Static route fast reroute (FRR) enables fast rerouting to minimize the impact of link or node failures.

Figure 1 Network diagram

As shown in Figure 1, upon a link failure, packets are directed to the backup next hop to avoid traffic interruption. Y ou can either specify a backup next hop for FRR or enable FRR to automatically select a backup next hop (which must be configured in advance).

Configuration guidelines

Do not use static route FRR and BFD (for a static route) at the same time. Static route does not take effect when the backup output interface is unavailable. Equal-cost routes do not support static route FRR. The backup output interface and next hop must be different from the primary output interface

To change the backup output interface or next hop, you must first remove the current setting. Static route FRR is available only when the state of primary link (with Layer 3 interfaces staying

Configuring static route FRR by specifying a backup next hop

1. Enter system view.

and next hop.

up) changes from bidirectional to unidirectional or down.

system-view

• Method 1:

ip route-static dest-address { mask-length | mask } interface-type interface-number [ next-hop-address [ backup-interface interface-type

interface-number [ backup-nexthop backup-nexthop-address

[ permanent ] [ preference preference ] [ tag tag-value ] [ description text ]

FRR.

• Method 2: ip route-static vpn-instance s-vpn-instance-name dest-address { mask-length | mask } interface-type interface-number [ next-hop-address [ backup-interface interface-type

interface-number [ backup-nexthop backup-nexthop-address

[ permanent ] [ preference preference ] [

tag-value ] [

text ]

N/A

is disabled.

Step

Command

Remarks

system-view

FRR is

Step

Command

Remarks

Configure the source IP address of BFD echo

echo packets is not

High Availability

Enable BFD echo packet

By default, BFD echo mode for

Task

Command

Display static route next hop

ing table

Configuring static route FRR to automatically select a backup next hop

1. Enter system view.

2. Configure static route FRR to

automatically select a backup next hop.

ip route-static fast-reroute auto

N/A By default, static route

disabled from automatically selecting a backup next hop.

Enabling BFD echo packet mode for static route FRR

By default, static route F RR uses ARP to detec t primary link f ailures. Perform this task to enable static route FRR to use BFD echo packet mode for fast failure detection on the primary link.

To enable BFD echo packet mode for static route FRR:

1. Enter system view.

packets.

system-view

bfd echo-source-ip

ip-address

N/A By default, the source IP address

of BFD configured.

The source IP address cannot be on the same network segment as any local interface's IP address.

For more information about this command, see Command Reference.

mode for static route FRR.

ip route-static primary-path-detect bfd echo

static route FRR is disabled.

Displaying and maintaining static routes

Execute display commands in any view.

Display static route information.

information. Display static rout

information.

display ip routing-table protocol static

display route-static nib

display route-static routing-table

vpn-instance-name ] [ ip-address { mask-length | mask } ]

[ nib-id ] [

[

verbose ]

inactive

[

verbose ]

vpn-instance

Vlan-int100

1.1.6.1/24

Host B

1.1.6.2/24

Vlan-int500

1.1.4.2/30

Vlan-int600

1.1.5.5/30

Vlan-int500

1.1.4.1/30

Vlan-int600

1.1.5.6/30

Vlan-int900

1.1.3.1/24

Vlan-int300

1.1.2.3/24

Host A

1.1.2.2/24

Host C

1.1.3.2/24

Switch B

Switch A

Switch C

Static route configuration examples

Basic static route configuration example

Network requirements

As shown in Figure 2, c onf i gure s tat ic routes on th e switches for interc onnections between an y t wo hosts.

Figure 2 Network diagram

Configuration procedure

1. Configure IP addresses for interfaces. (Details not shown.)

2. Configure static routes:

# Configure a default route on Switch A.

<SwitchA> system-view [SwitchA] ip route-static 0.0.0.0 0.0.0.0 1.1.4.2

# Configure two static routes on Switch B.

<SwitchB> system-view [SwitchB] ip route-static 1.1.2.0 255.255.255.0 1.1.4.1 [SwitchB] ip route-static 1.1.3.0 255.255.255.0 1.1.5.6

# Configure a default route on Switch C.

<SwitchC> system-view [SwitchC] ip route-static 0.0.0.0 0.0.0.0 1.1.5.5

3. Configure the default gateways of Host A, Host B, and Host C as 1.1.2.3, 1.1.6.1, and 1.1.3.1. (Details not shown.)

Verifying the configuration

# Display static routes on Switch A.

[SwitchA] display ip routing-table protocol static

Summary Coun t : 1

Static Routing table Status : <Ac ti ve> Summary Coun t : 1

Destination/M ask Proto Pre Cost NextHop Interface

0.0.0.0/0 Static 60 0 1.1.4.2 Vlan500

Static Routing ta ble Status : <Inac tive> Summary Coun t : 0

# Display static routes on Switch B.

[SwitchB] display ip routing-table protocol static

Summary Coun t : 2

Static Routing table Status : <Ac ti ve> Summary Coun t : 2

Destination/Mask Proto Pre Cost NextHop Interface

1.1.2.0/24 Static 60 0 1.1.4.1 Vlan500

Static Routing table Status : <In ac tive> Summary Coun t : 0

# Use the ping command on Host B to test the reachability of Host A (Windows XP runs on the two hosts).

C:\Documents an d Settings\Administrator>ping 1.1.2.2

Pinging 1.1.2.2 with 32 bytes of data :

Reply from 1.1.2.2: bytes=32 time=1ms TTL=126 Reply from 1.1 .2.2: bytes=32 tim e=1ms TTL=126 Reply from 1.1 .2.2: bytes=32 tim e=1ms TTL=126 Reply from 1.1 .2.2: bytes=32 tim e=1ms TTL=126

Ping statist ics for 1.1.2.2: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximat e round trip times in milli-seconds: Minimum = 1ms, Maximum = 1ms, Average = 1ms

# Use the tracert command on Host B to test the reachability of Host A.

C:\Documents an d Settings\Administrator>tracert 1.1.2.2

Tracing rout e to 1.1.2.2 over a maxi mum of 30 hops

1 <1 ms <1 ms <1 ms 1.1.6.1 2 <1 ms <1 ms <1 ms 1.1.4.1 3 1 ms <1 ms <1 ms 1.1.2.2

Trace complete.

BFD for static routes configuration ex am ple (direct next hop)

Network requirements

Configure the following, as shown in Figure 3:

•

Device

Interface

IP address

Switch A Switch B

Switch C

BFD

Switch

Vlan-int10

Vlan

-int

Vlan-int11

Vlan

-int

Vlan-

int13

Vlan-int10

121.

120.1.1.0/24

Configure a static route to subnet 120.1.1.0/24 on Switch A. Configure a static route to subnet 121.1.1.0/ 24 on S wit c h B. Enable BFD for both routes. Configure a static route to subnet 120.1.1.0/24 and a static route to subnet 121.1.1.0/24 on

Switch C.

When the link between Switch A and Switch B throu gh the Layer 2 switch fails, B FD c an det ec t th e failure immediately. Switch A then communicates with Switch B through Switch C.

Figure 3 Network diagram

Table 4 Interface and IP address assignment

Switch A VLAN-interface 10 12.1.1.1/24 Switch A VLAN-interface 11 10.1.1.102/24 Switch B VLAN-interface 10 12.1.1.2/24 Switch B VLAN-interface 13 13.1.1.1/24 Switch C VLAN-interface 11 10.1.1.100/24 Switch C VLAN-interface 13 13.1.1.2/24

Configuration procedure

1. Configure IP addresses for the interfaces. (Details not shown.)

2. Configure static routes and BFD:

# Configure static routes on Switch A and enable BFD control mode for the static route that traverses the Layer 2 switch.

<SwitchA> system-view [SwitchA] interface vlan-interface 10 [SwitchA-vlan-interface10] bfd min-transmit-interval 500 [SwitchA-vlan-interface10] bfd min-receive-interval 500 [SwitchA-vlan-interface10] bfd detect-multiplier 9 [SwitchA-vlan-interface10] quit [SwitchA] ip route-static 120.1.1.0 24 vlan-interface 10 12.1.1.2 bfd control-packet [SwitchA] ip route-static 120.1.1.0 24 vlan-interface 11 10.1.1.100 preference 65 [SwitchA] quit

# Configure static routes on Switch B and enable BFD control mode for the static route that traverses the Layer 2 switch.

<SwitchB> sy stem-view [SwitchB] interface vlan-interface 10

[SwitchB-vlan-interface10] bfd min-transmit-interval 500 [SwitchB-vlan-interface10] bfd min-receive-interval 500 [SwitchB-vlan-interface10] bfd detect-multiplier 9 [SwitchB-vlan-interface10] quit [SwitchB] ip route-static 121.1.1.0 24 vlan-interface 10 12.1.1.1 bfd control-packet [SwitchB] ip route-static 121.1.1. 0 24 vlan-interface 13 13.1.1.2 preference 65 [SwitchB] qu it

# Configure static routes on Switch C.

<SwitchC> sy stem-view [SwitchC] ip rout e-static 120.1.1.0 24 13.1.1.1 [SwitchC] ip rout e-static 121.1.1.0 24 10.1.1.102

Verifying the configuration

# Display BFD sessions on Switch A.

<SwitchA> display bfd session

Total Session Nu m: 1 Up Session Num: 1 Init Mode: Ac tive

IPv4 Session Working Under Ctrl Mode:

LD/RD SourceAddr DestAddr State Holdtime Interface 4/7 12.1.1.1 12.1.1.2 Up 2000ms Vlan10

The output shows that the BFD session has been created. # Display the static routes on Switch A.

<SwitchA> display ip routing-table protocol static

Summary Count : 1

Static Routing table Status : <Ac ti ve> Summary Coun t : 1

Destination/Mask Proto Pre Cost NextHop Interface

120.1.1.0/24 Static 60 0 12. 1.1.2 Vlan10

Static Routing ta ble Status : <Inac tive> Summary Count : 0

The output shows that Swit ch A communicates with Sw itch B thr ough VLAN-interface 10. Then the link over VLAN-interface 10 fails.

# Display static routes on Switch A.

<SwitchA> display ip routing-table protocol static

Summary Coun t : 1

Static Routing table Status : <Ac ti ve> Summary Coun t : 1

Destination/Mask Proto Pre Cost NextHop Interface

120.1.1.0/24 Static 65 0 10. 1.1.100 Vlan11

•

Device

Interface

IP address

Switch A Switch B

Switch C

BFD

Vlan-int10

Vlan

int

Vlan-int11 Vlan-int13

Vlan-

int

Vlan-int10

121.1.1.0/24

120.1.1.0/24

Switch D

Vlan-int12

Loop1

1.1.1.9/32

Loop1

2.2.2.9/32

Static Routing ta ble Status : <Inac tive> Summary Coun t : 0

The output shows that Switch A communicates with Switch B through VLAN-interface 11.

BFD for static routes configuration ex am ple (indirect next hop)

Network requirements

Figure 4 shows the network topology as follows:

Switch A has a route to interface Loopback 1 (2.2.2.9/32) on Switch B, with the output interface

VLAN-interface 10.

Switch B has a route to interface Loopback 1 (1.1.1.9/32) on Switch A, with the output interface

VLAN-interface 12.

Switch D has a route to 1.1.1.9/32, with the output interface VLAN-interface 10, and a route to

2.2.2.9/32, with the output interfac e VLAN-interface 12.

Configure the following:

Configure a static route to subnet 120.1.1.0/24 on Switch A. Configure a static route to subnet 121.1.1.0/24 on Switch B. Enable BFD for both routes. Configure a static route to subnet 120.1.1.0/24 and a static route to subnet 121.1.1.0/24 on both

Switch C and Switch D.

When the link between Switch A and Switch B through Switch D fails, BFD can detect the failure immediately. Switch A then communicates with Switch B through Switch C.

Figure 4 Network diagram

Table 5 Interface and IP address assignment

Switch A VLAN-interface 10 12.1.1.1/24 Switch A VLAN-interface 11 10.1.1.102/24 Switch A Loopback 1 1.1.1.9/32 Switch B VLAN-interface 12 11.1.1.1/24 Switch B VLAN-interface 13 13.1.1.1/24 Switch B Loopback 1 2.2.2.9/32

Device

Interface

IP address

Switch C VLAN-interface 11 10.1.1.100/24 Switch C VLAN-interface 13 13.1.1.2/24 Switch D VLAN-interface 10 12.1.1.2/24 Switch D VLAN-interface 12 11.1.1.2/24

Configuration procedure

1. Configure IP addresses for interfaces. (Details not shown.)

2. Configure static routes and BFD:

# Configure static routes on Switch A and enable BFD control mode for the static route that traverses Switch D.

<SwitchA> system-view [SwitchA] bf d multi-hop min-transmit-interval 500 [SwitchA] bf d multi-hop min-receive-interval 500 [SwitchA] bfd multi-hop detect-multiplier 9 [SwitchA] ip route-static 120.1.1.0 24 2.2.2.9 bfd control-packet bfd-source 1.1.1.9 [SwitchA] ip route-static 120.1.1.0 24 vlan-interface 11 10.1.1.100 preference 65 [SwitchA] quit

# Configure static routes on Switch B and enable BFD control mode for the static route that traverses Switch D.

<SwitchB> sy stem-view [SwitchB] bfd multi-hop min-transmit-interval 500 [SwitchB] bfd multi-hop min-receive-interval 500 [SwitchB] bfd multi-hop detect-multiplier 9 [SwitchB] ip route-static 121.1.1.0 24 1.1.1.9 bfd control-packet bfd-source 2.2.2.9 [SwitchB] ip route-static 121.1.1. 0 24 vlan-interface 13 13.1.1.2 preference 65 [SwitchB] qu it

# Configure static routes on Switch C.

<SwitchC> sy stem-view [SwitchC] ip rout e-static 120.1.1.0 24 13.1.1.1 [SwitchC] ip rout e-static 121.1.1.0 24 10.1.1.102

# Configure static routes on Switch D.

<SwitchD> sy stem-view [SwitchD] ip rout e-static 120.1.1.0 24 11.1.1.1 [SwitchD] ip rout e-static 121.1.1.0 24 12.1.1.1

Verifying the configuration

# Display BFD sessions on Switch A.

<SwitchA> display bfd session

Total Session Nu m: 1 Up Session Num: 1 Init Mode: Ac tive

IPv4 Session Working Under Ctrl Mode:

LD/RD SourceAddr DestAddr State Holdtime Interf ace 4/7 1.1.1.9 2.2.2.9 Up 2000ms N/A

The output shows that the BFD session has been created.

Switch A Switch B

Switch C

Loop0

Vlan-int100

Vlan-

int200

Vlan-int200

Vlan-int100

Vlan

-int101

Vlan-int101

Loop0

Link A

Link B

# Display the static routes on Switch A.

<SwitchA> display ip routing-table protocol static

Summary Coun t : 1

Static Routing table Status : <Ac ti ve> Summary Coun t : 1

Destination/Mask Proto Pre Cost NextHop Interface

120.1.1.0/24 Static 60 0 12.1.1.2 Vlan10

Static Routing ta ble Status : <Inac tive> Summary Coun t : 0

The output shows that Swit ch A communicates with Sw itch B thr ough VLAN-interface 10. Then the link over VLAN-interface 10 fails.

# Display static routes on Switch A.

<SwitchA> display ip routing-table protocol static

Summary Coun t : 1

Static Routing table Status : <Ac ti ve> Summary Coun t : 1

Destination/Mask Proto Pre Cost NextHop Interface

120.1.1.0/24 Static 65 0 10. 1.1.100 Vlan11

Static Routing ta ble Status : <Inac tive> Summary Coun t : 0

The output shows that Switch A communicates with Switch B through VLAN-interface 11.

Static route FRR configuration example

Network requirements

As shown in Figure 5, conf igure static routes on Switch A, Switch B, and Switch C, and configure static route FRR. When Link A becomes unidirectional, traffic can be switched to Link B immediately.

Figure 5 Network diagram

Device

Interface

IP address

Table 6 Interface and IP address assignment

Switch A VLAN-interface 100 12.12.12.1/24 Switch A VLAN-interface 200 13.13.13.1/24 Switch A Loopback 0 1.1.1.1/32 Switch B VLAN-interface 101 24.24.24.4/24 Switch B VLAN-interface 200 13.13.13.2/24 Switch B Loopback 0 4.4.4.4/32 Switch C VLAN-interface 100 12.12.12.2/24 Switch C VLAN-interface 101 24.24.24.2/24

Configuration procedure

1. Configure IP addresses for interfaces. (Details not shown.)

2. Configure static route FRR on link A by using one of the following methods:

 (Method 1.) Specify a backup next hop for static route FRR:

# Configure a static route on Switch A, and specify VLAN-interface 100 as the backup output interface and 12.12.12.2 as the backup next hop.

<SwitchA> system-view [SwitchA] ip route-static 4.4.4.4 32 vlan-interfa ce 200 13.13.13.2

backup-interface vlan-interface 100 backup-nexthop 12.12.12.2

# Configure a static route on Switch B, and specify VLAN-interface 101 as the backup output interface and 24.24.24.2 as the backup next hop.

<SwitchB> system-view [SwitchB] ip route-static 1.1.1.1 32 vlan-interfa ce 200 13.13.13.1

backup-interface vlan-interface 101 backup-nexthop 24.24.24.2

 (Method 2.) Configure static route FRR to automatically select a backup next hop:

# Configure static routes on Switch A, and enable static route FRR.

<SwitchA> system-view [SwitchA] ip route-static 4.4.4.4 32 vlan-interface 20 0 13.13.13.2 [SwitchA] ip route-static 4.4.4.4 32 vl an-interface 100 12.12. 12.2 preference 70 [SwitchA] ip route-static fast-reroute auto

# Configure static routes on Switch B, and enable static route FRR.

<SwitchB> system-view [SwitchB] ip route-static 1.1.1.1 32 vlan-interfac e 200 13.13.13.1 [SwitchB] ip route-static 1.1.1.1 32 vl an-interface 101 24.24.24.2 preference 70 [SwitchB] ip route-static fast-reroute auto

3. Configure static routes on Switch C.

<SwitchC> system-view [SwitchC] ip route-static 4.4.4.4 32 vlan-interfa ce 101 24.24.24.4 [SwitchC] ip route-static 1.1.1.1 32 vlan-interfa ce 100 12.12.12.1

Verifying the configuration

# Display route 4.4.4.4/32 on Switch A to view the backup next hop information.

[SwitchA] display ip routing-table 4.4.4.4 verbose

Summary Coun t : 1

Destination: 4. 4.4.4/32 Protocol: Static Process ID: 0 SubProtID: 0x0 Age: 04h20m37s Cost: 0 Preference: 60 IpPre: N/A QosLocalID: N/A Tag: 0 State: Active Adv OrigTblID: 0x0 OrigVrf: default-vrf TableID: 0x2 OrigAs: 0 NibID: 0x 26000002 LastAs: 0 AttrID: 0x ffffffff Neighbor: 0.0. 0.0 Flags: 0x1008c OrigNextHop: 13.13.13.2 Label: NULL RealNextHop: 13.13.13.2 BkLabel: NULL BkNextHop: 12.12.12.2 Tunnel ID: Inva lid Interface: Vlan-interface200 BkTunnel ID: Inva lid BkInterface: Vlan -interface100 FtnIndex: 0x0 TrafficIndex: N/A Connector: N/A

# Display route 1.1.1.1/32 on Switch B to view the backup next hop information.

[SwitchB] display ip routing-table 1.1.1.1 verbose

Summary Count : 1

Destination: 1.1.1.1/32 Protocol: Static Process ID: 0 SubProtID: 0x0 Age: 04h20m37s Cost: 0 Preference: 60 IpPre: N/A QosLocalID: N/A Tag: 0 State: Active Adv OrigTblID: 0x0 OrigVrf: default-vrf TableID: 0x2 OrigAs: 0 NibID: 0x 26000002 LastAs: 0 AttrID: 0x ffffffff Neighbor: 0.0. 0.0 Flags: 0x1008c OrigNextHop: 13.13.13.1 Label: NULL RealNextHop: 13.13.13.1 BkLabel: NULL BkNextHop: 24.24.24.2 Tunnel ID: Inva lid Interface: Vlan-interface200 BkTunnel ID: Inva lid BkInterface: Vlan-interface101 FtnIndex: 0x0 TrafficIndex: N/A Connector: N/A

•

Configuring a default route

A default route is used to forward packets that do not match any specific routing entry in the routing table. Without a default route, packets that do not match any routing entries are discarded.

A default route can be configured in either of the following ways:

The network administrator can configure a default r out e with both des ti nat ion an d mask being

0.0.0.0. For more information, see "Configuring static routing."

Some dynamic routing protocols, such as OSPF, IS-IS, and RIP, can generate a default route.

For example, an upstream router running OSPF can generate a default route and advertise it to other routers. These routers install the default route with the next hop being the upstream router. For more information, see the respective chapters on these routing protocols in this configuration guide.

•

Configuring RIP

Overview

Routing Information Protocol (RIP) is a distance-vector IGP suited to small-sized networks. It employs UDP to exchange route inform ation through port 520.

RIP uses a hop count to meas ure the distance to a d estination. The hop c ount from a router to a directly connected net work is 0. T he hop count from a r outer to a direc tly connect ed router is 1. To limit convergence tim e, RI P restr icts the val ue ran ge of t he metric from 0 to 15. A destination with a metric value of 1 6 (or greater) is considered unreachabl e. For this reason, RI P is not suitable f or large-sized networks.

RIP route entries

RIP stores routing entries in a database. Each routing entry contains the following elements:

Destination address—IP address of a destination host or a network. Next hop—IP address of the next hop. Egress interface—Egress interface of the route. Metric—Cost from the local router to the destination. Route time—Time elapsed since the last update. The time is reset to 0 when the routing entry

is updated.

Route tag—Used for route control. For more information, see "Configuring routing policies."

Routing loop prevention

RIP uses the following mechanisms to prevent routing loops:

Counting to infinity—A destination with a metric value of 16 is considered unreachable. When

a routing loop occurs, the metric value of a route will increment to 16 to avoid endless looping.

Triggered updates—RIP immediately advertises triggered updates for topology changes to

reduce the possibility of routing loops and to speed up convergence.

Split horizon—Disables RIP from sending routes through the interface where the routes were

learned to prevent routing loops and save bandwidth.

Poison reverse—Enables RIP to set the metric of routes received from a neighbor to 16 and

sends these routes back to the neighbor. The neighbor can delete such information from its routing table to prevent routing loops.

RIP operation

RIP works as follows:

1. RIP sends request messages to neighboring routers. Neighboring routers return response messages that contain their routing tables.

2. RIP uses the received responses to update the local routing table and sends triggered update messages to its neighbors. All RIP routers on the network do this to learn latest routing information.

3. RIP periodically sends the local routing table to its neighbors. After a RIP neighbor receives the message, it updates its routing table, selects optimal routes, and sends an update to other neighbors. RIP ages routes to keep only valid routes.

•

Tasks at a glance

RIP versions

There are two RIP versions, RIPv1 and RIPv2. RIPv1 is a classful routing protocol. It advertises messages only through broadcast. RIPv1

messages do not car ry mask information, so RIPv1 c an only recognize natura l networks such as Class A, B, and C. For this reason, RIPv1 does not support discontiguous subnets.

RIPv2 is a classless routing protocol. It has the following advantages over RIPv1:

Supports route tags to implement flexible route control through routing policies. Supports masks, route summarization, and CIDR. Supports designated next hops to select the best ones on broadcast networks. Supports multicasting route updates so only RIPv2 routers can receive these updates to reduce

resource consumption.

Supports plain text authentication and MD5 authentication to enhance security.

RIPv2 supports two transm ission modes: broadcast and multicas t. Multicast is the default mode using 224.0.0.9 as the multicast address. An interface operating in RIPv2 broadcast mode can also receive RIPv1 messages.

Protocols and standards

RFC 1058, Routing Information Protocol RFC 1723, RIP Version 2 - Carrying Additional Information RFC 1721, RIP Version 2 Protocol Analysis RFC 1722, RIP Version 2 Protocol Applicability Statement RFC 1724, RIP Version 2 MIB Extension RFC 2082, RIPv2 MD5 Authentication RFC 2453, RIP Version 2

RIP configuration task list

Configuring basic RIP:

• (Required.) Enabling RIP

• (Optional.) Controlling RIP reception and advertisement on interfaces

• (Optional.) Configuring a RIP version

(Optional.) Configuring RIP route control:

• Configuring an additional routing metric

• Configuring RIPv2 route summarization

• Disabling host route reception

• Advertising a default route

• Configuring received/redistributed route filtering

• Setting a preference for RIP

• Configuring RIP route redistribution

•

Step

Command

Remarks

RIP and enter RIP

(Optional.) Tuning and optimizing RIP networks:

• Setting RIP timers

• Enabling split horizon and poison reverse

• Setting the maximum number of RIP ECMP routes

• Enabling zero field check on incoming RIPv1 messa ges

• Enabling source IP address check on incomi ng RIP updates

• Configuring RIPv2 message authentication

• Setting the RIP triggered update interval

• Specifying a RIP neighbor

• Configuring RIP network management

• Configuring the RIP packet sending rate

• Setting the maximum length of RIP packets

• Setting the DSCP value for outgoing RIP packets

(Optional.) Configuring RIP GR (Optional.) Enabling RIP NSR (Optional.) Configuring BFD for RIP (Optional.) Configuring RIP FRR

Configuring basic RIP

Before you configure basic RIP settings, complete the following tasks:

Configure the link layer protocol. Configure IP addresses for interfaces to ensure IP connectivity between neighboring routers.

Enabling RIP

Follow these guidelines when you enable RIP:

To enable multiple RIP processes on a router, you must specify an ID for each process. A RIP

process ID has only local significance. Two RIP routers having different process IDs can also exchange RIP packets.

If you configure RIP settings in interface view before enabling RIP, the settings do not take

effect until RIP is enabled.

If a physical interface is attached to multiple networks, you cannot advertise these networks in

different RIP processes.

You cannot enable multiple RIP processes on a physical interface. The rip enable command takes precedence over the network command.

Enabling RIP on a network

You can enable RIP on a network and specif y a wildc ard m ask for the net work. Af ter that, on ly the interface attached to the network runs RIP.

To enable RIP on a network:

1. Enter system view.

2. Enable

view.

system-view rip

[ process-id ] [

vpn-instance-name ]

vpn-instance

N/A

By default, RIP is disabled.

Step

Command

Remarks

, but does not

Step

Command

Remarks

RIP and enter RIP

exclude-subip

Step

Command

Remarks

interface from

The disabled interface can still

messages and

respond to unicast requests

interface to

interface to send

interface can send RIP

3. Enable RIP on a network.

Enabling RIP on an interface

network

[ wildcard-mask ]

network-address

By default, RIP is disabled on a network.

network

The can enable RIP on al l interf aces i n a single process apply to multiple RIP processes.

0.0.0.0 command

1. Enter system view.

2. Enable

view.

3. Return to system view.

4. Enter interface view.

5. Enable RIP on the interface.

system-view rip

[ process-id ] [

vpn-instance-name ]

quit interface

interface-number

rip

[

interface-type

process-id

]

vpn-instance

enable

N/A

By default, RIP is disabled.

N/A

By default, RIP is disabled on an interface.

Controlling RIP reception and adverti sement on interfaces

1. Enter system view.

2. Enter RIP view.

3. Disable an

sending RIP messages.

system-view rip

[ process-id ] [

vpn-instance-name ]

silent-interface

interface-number |

{ interface-type

all

vpn-instance

}

N/A

By default, all RIP-enabled interfaces can send RIP messages.

receive RIP

4. Return to system view.

5. Enter interface view.

6. Enable an

receive RIP messages.

7. Enable an RIP messages.

Configuring a RIP version

You can configure a global RIP version in RI P view or an interface-specif ic RI P version in interface view.

quit interface

interface-number

rip input

rip output

interface-type

containing unknown ports. N/A

N/A

By default, a RIP-enabled interface can receive RIP messages.

By default, a RIP-enabled messages.

•

Step

Command

Remarks

system-view

, no global version is

interface sends

RIPv1 broadcasts, and can

RIPv2 broadcasts,

specified. The interface sends RIPv1 broadcasts, and can receive

•

Step

Command

Remarks

An interface preferent ially us es the interf ace-spec ific RIP version. If no interf ace-spe cific versio n is specified, the inter face uses the global RIP version. If neither a global nor interfac e-specific RIP version is configured, the interface sends RIPv1 broadcasts and can receive the following:

RIPv1 broadcasts and unicasts. RIPv2 broadcasts, multicasts, and unicasts.

To configure a RIP version:

1. Enter system view.

2. Enter RIP view.

3. Specify a global RIP version.

4. Return to system view.

5. Enter interface view.

6. Specify a RIP version for the

interface.

rip

[ process-id ] [

vpn-instance-name ]

version

quit interface

interface-number

rip version multicast

{ 1 | 2 }

interface-type

{ 1 | 2 [

] }

vpn-instance

broadcast

Configuring RIP route control

N/A

By default specified. An

receive RIPv1 broadcasts and unicasts, and multicasts, and unicasts.

N/A

By default, no interface-specific RIP version is

RIPv1 broadcasts and unicasts, and RIPv2 broad casts, multi casts, and unicasts.

Before you configure RIP route control, complete the following tasks:

Configure IP addresses for interfaces to ensure IP connectivity between neighboring routers. Configure basic RIP.

Configuring an add i tional routing metric

An additional routing m etric ( hop count) c an be ad ded to the metr ic of an inbound or outbound RIP route.

An outbound additional metric is added to the metric of a sent route, and it does not c hange the route's metric in the routing table.

An inbound additional metric is added to the metric of a received route before the route is added into the routing table, and the route's metric is changed. If the sum of the addition al metric and the original metric is greater than 16, the metric of the route is 16.

To configure additional routing metrics:

1. Enter system view.

system-view

N/A

Step

Command

Remarks

Step

Command

Remarks

automatic route

Step

Command

Remarks

Disable RIPv2 automatic

2. Enter interface view.

3. Specify an inbound

additional routing metric.

4. Specify an outbound additional routing metric.

interface

interface-number

rip metricin

route-policy-name ] value

rip metricout

route-policy-name ] value

interface-type

route-policy

[

route-policy

[

Configuring RI P v2 route summarization

Perform this task to summarize contiguous subnets into a summary network and sends the network to neighbors. The smallest metric among all summarized routes is used as the metric of the summary route.

Enabling RIPv2 automatic route summarization

Automatic summarization enables RIP v2 t o ge ner at e a natur a l net work for contiguous subnets. F or example, suppose there are three subnet routes 10.1.1.0/24, 10.1.2.0/24, and 10.1.3.0/24. Automatic summ ar ization a utomatically creates and advertises a summ ar y route 1 0.0.0 . 0/8 inste ad of the more specific routes.

To enable RIPv2 automatic route summarization:

1. Enter system view.

system-view

N/A

The default setting is 0.

The default setting is 1.

N/A

2. Enter RIP view.

3. (Optional.) Enable RIPv2

summarization.

Advertising a summary route

Perform this task to manually configure a summary route. For example, suppose cont iguous subne ts routes 10.1 .1.0/24, 10 .1. 2.0/2 4, and 1 0.1.3.0/2 4 exist in

the routing table. You can create a summ ary route 10.1.0.0/16 on Hundr edGigE 1/0/1 to advertise the summary route instead of the more specific routes.

To configure a summary route:

1. Enter system view.

2. Enter RIP view.

route summarization.

4. Return to system view.

rip

[ process-id ] [

vpn-instance-name ]

summary

system-view rip

[ process-id ] [

vpn-instance-name ]

undo summary

quit

vpn-instance

N/A

By default, RIPv2 automatic route summarization is enabled.

If subnets in the routing table are not contiguous, disable automatic route summarization to advertise more specific routes.

N/A

By default, RIPv2 automatic route summarization is enabled.

N/A

5. Enter interface view.

interface

interface-number

interface-type

N/A

Step

Command

Remarks

no summary route is

Step

Command

Remarks

from receiving

By default, RIP receives host

Step

Command

Remarks

system-view

Enable RIP to advertise a

Configure the RIP interface

By default, a RIP interface can

NOTE:

The router enabled to advertise a default route does not accept default routes from RIP neighbors.

6. Configure a summary route.

rip summary-address

ip-address

Disabling host r oute reception

Perform this task to disable RIPv2 from receiving host routes from the same network to save network resources. This feature does not apply to RIPv1.

To disable RIP from receiving host routes:

1. Enter system view.

2. Enter RIP view.

3. Disable RIP

host routes.

system-view rip

[ process-id ] [

vpn-instance-name ]

undo host-route

Advertising a def ault route

You can advertise a default route on all RIP interfaces in RIP view or on a specific RIP interf ace in interface view. The interface view setting takes precedence over the RIP view settings.

{ mask-length | mask }

vpn-instance

By default, configured.

N/A

routes.

To disable an interface from advertising a default route, use the rip default-route no-originate command on the interface.

To configure RIP to advertise a default route:

1. Enter system view.

2. Enter RIP view.

default route.

4. Return to system view.

5. Enter interface view.

to advertise a default route.

rip

[ process-id ] [

vpn-instance-name ]

default-route

cost

[

cost-value |

route-policy-name ] *

quit interface

interface-number

rip default-route originate route-policy

no-originate

* |

only

{

interface-type

{ {

cost

} [

route-policy-name ]

}

vpn-instance

originate

route-policy

only

cost-value |

N/A

}

By default, RIP does not adver tise a default route.

N/A

advertise a default route if the RIP process is enabled to advertise a default route.

Configuring received/redistributed route filtering

Perform this task to filter received and redistributed routes by using a filtering policy.

Step

Command

Remarks

Configure the filtering of

By default, the filtering of

command filters received

routes. Filtered routes are not

By default, the filtering of redistributed routes is not

command filters redistributed routes, including routes redistributed with the

Step

Command

Remarks

Step

Command

Remarks

To configure route filtering:

1. Enter system view.

2. Enter RIP view.

received routes.

4. Configure the filtering of redistributed routes.

system-view rip

[ process-id ] [

vpn-instance-name ]

filter-policy gateway

prefix-list-name [ prefix-list-name ] } [ interface-type interface-number ]

filter-policy prefix-list

[ protocol [ process-id ] | interface-type interface-number ]

prefix-list-name |

Setting a preference for RIP

If multiple IGPs find rou tes to the s ame destination, the r oute f oun d by the IGP that has the highest priority is selected as the optimal route. Perform this task to assign a preference to RIP. The smaller the preference value, the higher the priority.

vpn-instance

{ ipv4-acl-number |

prefix-list

gateway

import

{ ipv4-acl-number |

prefix-list-name }

export

N/A

received routes is not configured.

This installed into the routing table or

advertised to neighbors.

configured. This

import-route

command.

To set a preference for RIP:

1. Enter system view.

2. Enter RIP view.

3. Set a preference for RIP.

system-view rip

[ process-id ] [

vpn-instance-name ]

preference route-policy

{ preference |

route-policy-name }

vpn-instance

Configuring RI P route redistribution

Perform this task to configure RIP to redistribute routes from other routing protocols, including OSPF , IS-IS, BGP, static, and direct.

To configure RIP route redistribution:

1. Enter system view.

2. Enter RIP view.

system-view rip

[ process-id ] [

vpn-instance-name ]

vpn-instance

N/A

The default setting is 100.

N/A

Step

Command

Remarks

s from

RIP route

This command can redistribute

display ip

•

IMPORTANT:

To avoid unnecessary traffic or route flapping, configure identical RIP timer settings on RIP routers.

Step

Command

Remarks

By default, redistribution is disabled.

]

only active routes. To view active routes, use the

routing-table

command. The default setting is 0.

3. Redistribute route another routing protocol.

4. (Optional.) Set a default cost for redistributed routes.

import-route

[ as-number ] [ process-id |

all-processes

allow-direct

[

route-policy tag

tag ] *

default cost

allow-ibgp

cost

route-policy-name |

cost-value

protocol

cost-value |

Tuning and optimizing RIP networks

Configuration prerequisites

Before you tune and optimize RIP networks, complete the following tasks:

Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes. Configure basic RIP.

Setting RIP timers

You can change the RIP network convergence speed by adjusting the following RIP ti mers:

Update timer—Specifies the interval between route updates. Timeout timer—Specifies the route aging time. If no update for a route is received within the

aging time, the metric of the route is set to 16.

Suppress timer—Specifies how long a RIP route stays in suppressed state. When the metric

of a route is 16, the route enters the suppressed state. A suppressed route can be replaced by an updated route that is received from the same neighbor before the suppress timer expires and has a metric less than 16.

Garbage-collect timer—Specifies the interval from when the metric of a route becomes 16 to

when it is deleted from the routing table. RIP advertises the route with a metric of 16. If no update is announced for that route before the garbage-collect timer expires, the route is deleted from the routing table.

protocol

To set RIP timers:

1. Enter system view.

2. Enter RIP view.

system-view rip

[ process-id ] [

vpn-instance-name ]

vpn-instance

N/A

Step

Command

Remarks

Step

Command

Remarks

, split horizon is

Step

Command

Remarks

Step

Command

Remarks

By default:

• The garbage-collect timer is 120

• The suppress timer is 120

• The timeout timer is 180 seconds.

• The update timer is 30 seconds.

3. Set RIP timers.

timers

garbage-collect-value | suppress-value | timeout-value | update-value } *

garbage-collect

{

suppress

timeout

update

Enabling split horizon and poison reverse

The split horizon and poison reverse functions can prevent routing loops. If both split horizon and poison reverse are configured, only the poison reverse function takes effect.

Enabling split horizon

Split horizon disables RIP from sending routes through the interface where the routes were learned to prevent routing loops bet ween adjacent routers.

To enable split horizon:

seconds.

1. Enter system view.

2. Enter interface view.

3. Enable split horizon.

system-view interface

interface-number

rip split-horizon

interface-type

N/A

By default enabled.

Enabling poison reverse

Poison reverse allows RIP to send routes through the interface where the routes were learned. The metric of these routes is always set to 16 (unreachable) to avoid routing loops between neighbors.

To enable poison reverse:

1. Enter system view.

2. Enter interface view.

3. Enable poison reverse.

system-view interface

interface-number

rip poison-reverse

interface-type

N/A

By default, poison reverse is disabled.

Setting the maxim um number of RIP ECMP routes

Perform this task to implement load sharing over ECMP routes. To set the maximum number of RI P ECMP routes:

1. Enter system view.

system-view

N/A

Step

Command

Remarks

equals the

maximum number of ECMP

Step

Command

Remarks

Step

Command

Remarks

check on incoming RIP

By default, this function is

2. Enter RIP view.

3. Set the maximum number of

RIP ECMP routes.

rip

[ process-id ] [

vpn-instance-name ]

maximum load-balancing

number

vpn-instance

N/A

By default, the maximum number of RIP ECMP routes

routes supported by the system.

Enabling zero field check on incoming RIPv1 messages

Some fields in the RIPv1 message must be set to zero. These fields are called "zero fields." Y ou can enable zero field check on incoming RIPv1 messages. If a zero field of a message contains a non-zero value, RIP does not process the message. If you are certain that all messages are trustworthy, disable zero field check to save CPU resources.

This feature does not apply to RIPv2 packets, because they have no zero fields. To enable zero field check on incoming RIPv1 messages:

1. Enter system view.

2. Enter RIP view.

3. Enable zero field check on

incoming RIPv1 messages.

system-view rip

[ process-id ] [

vpn-instance-name ]

checkzero

vpn-instance

N/A

The default setting is enabled.

Enabling source IP address check on incoming RIP updates

Perform this task to enable source IP address check on incoming RIP updates. Upon receiving a message on an Etherne t interface, RIP compares the source IP address of the

message with the IP addr ess of the interface. If the y are not in the same network segment, RIP discards the message.

Upon receiving a message on a PPP interface, RIP checks whether the source address of the message is the IP address of the peer interface. If not, RIP discards the message.

To enable source IP address check on incoming RIP updates:

1. Enter system view.

2. Enter RIP view.

3. Enable source IP address

messages.

system-view rip

[ process-id ] [

vpn-instance-name ]

validate-source-address

vpn-instance

N/A

enabled.

Configuring RI P v2 message authent i c ation

Perform this task to enable authentication on RIPv2 messages. This feature does not apply to RIPv1 because RIPv1 does not support authentic ation. A lthough you can sp ecify an authent ication m ode for RIPv1 in interface view, the configuration does not take effect.

Step

Command

Remarks

By default, RIPv2

is not

•

Step

Command

Remarks

Set the RIP triggered

•

RIPv2 supports two authentication modes: simple authentication and MD5 authentication. To configure RIPv2 message authentication:

1. Enter system view.

2. Enter interface view.

3. Configure RIPv2

authentication.

system-view interface rip authentication-mode

cipher

{

cipher

{

plain }

interface-type interface-number

plain

string }

} string key-id |

} string } |

md5

{

simple { cipher

Setting the RIP t riggered update inter v al

Perform this task to avoid network overh ead and r educe system resource cons umption caused by frequent RIP triggered updates.

You can use the timer triggered comm and to set the maximum interval, minimum interva l, and incremental interval for sending RIP triggered updates.

For a stable network, the minimum-interval is used. If network changes become frequent, the incremental interval incremental-interval is used to

extend the triggered update sending int er val unti l the maximum-interval is reached.

To set the triggered update interval:

1. Enter system view.

system-view

rfc2082 rfc2453

N/A N/A

authentication configured.

N/A

rip

2. Enter RIP view.

update interval.

[ process-id ] [

vpn-instance-name ]

timer triggered

[ minimum-interval [ incremental-interval ] ]

Specifying a RIP nei ghbor

Typically RIP m essages are sent in broadcast or multicast. To enable RIP on a link that does n ot support broadcast or multicast, you must manually specify RIP neighbors.

Follow these guidelines when you specify a RIP neighbor:

Do not use the peer ip-address command when the neighbor is directly connected. Otherwise,

the neighbor might receive both unicast and multicast (or broadcast) messages of the same routing information.

If the specified neighbor is not directly connected, disable source address check on incoming

updates.

To specify a RIP neighbor:

vpn-instance

maximum-interval

N/A

By default:

• The maximum interval is 5 seconds.

• The minimum interval is 50 milliseconds.

• The incremental interval is 200 milliseconds.

Step

Command

Remarks

By default, RIP does not unicast updates to any

Disable source IP

source IP

Step

Command

Remarks

Bind MIB to a RIP

is bound to the

with the smallest

Step

Command

Remarks

Set the interval for sending maximum number of RIP

By default, an interface sends up to three RIP packets every 20

Set the interval for sending maximum number of RIP

RIP packet sending rate configured for the RIP process

1. Enter system view.

2. Enter RIP view.

3. Specify a RIP neighbor.

address check on inbound RIP updates

system-view rip

[ process-id ] [

vpn-instance-name ]

peer

ip-address

undo validate-source-address

Configuring RI P network management

You can use network management software to manage the RIP process to which MIB is bound. To configure RIP network management:

1. Enter system view.

process.

system-view

rip mib-binding

process-id

vpn-instance

N/A By default, MIB

RIP process process ID.

N/A

peer. By default,

address check on inbound RIP updates is enabled.

Configuring the RIP packet sending rat e

Perform this task to set the interval for sending RIP packets and the maximum number of RIP packets that can be sent at each interval. This feature can avoid excessive RIP packets from affecting system performance and consuming too much bandwidth.

To configure the RIP packet sending rate:

1. Enter system view.

2. Enter RIP view.

RIP packets and the packets that can be sent at

each interval.

4. Return to system view.

5. Enter interface view.

RIP packets and the packets that can be sent at

each interval.

system-view rip

[ process-id ] [

vpn-instance-name ]

output-delay

quit interface

interface-number

rip output-delay

count

interface-type

time

count

vpn-instance

count

time

N/A

milliseconds.

N/A

By default, the inter face uses t he

that the interface runs.

CAUTION:

The supported maximum length of RIP packets varies by vendor avoid compatibility issues.

•

Step

Command

Remarks

Set the maximum length of

Step

Command

Remarks

Set the DSCP value for

By default, the DSCP value for

•

Setting the maximum l ength of RIP packet s

. Use this feature with caution to

The packet length of RI P pack et s determines how m an y routes c a n be car r ied in a R I P pack et. S et the maximum length of RIP packets to make good use of link bandwidth.

When authentication is enabled, follow these guidelines to ensure packet forwarding:

For simple authentication, the maximum length of RIP packets must be no less than 52 bytes. For MD5 authentication (with packet format defined in RFC 2453), the maximum length of RIP

packets must be no less than 56 bytes.

For MD5 authentication (with packet format defined in RFC 2082), the maximum length of RIP

packets must be no less than 72 bytes.

To set the maximum length of RIP packets:

1. Enter system view.

2. Enter interface view.

RIP packets.

system-view interface

interface-number

rip max-packet-length

interface-type

value

N/A

By default, the maximum l ength of RIP packets is 512 bytes.

Setting the DSCP value for outgoing RIP packets

The DSCP value specifies the precedence of outgoing packets. To set the DSCP value for outgoing RIP packets:

1. Enter system view.

2. Enter RIP view.

outgoing RIP packets.

system-view rip

[ process-id ] [

vpn-instance-name ]

dscp

dscp-value

vpn-instance

N/A

outgoing RIP packets is 48.

Configuring RIP GR

GR ensures forwar ding cont inuity wh en a r outing prot ocol res tarts or an act ive/standb y switc hover occurs.

Two routers are required to complete a GR process. The following are router roles in a GR process:

GR restarter—Graceful restarting router. It must have GR capability. GR helper—A neighbor of the GR restarter. It helps the GR restarter to complete the GR

process.

After RIP restarts on a router, the router must learn RIP routes again and update its FIB table, which causes network disconnections and route reconvergence.

IMPORTANT:

You cannot enable RIP NSR on a device that acts as GR restarter.

Step

Command

Remarks

(Optional.) Set the GR

By default, the GR interval is 60

IMPORTANT:

A device that has RIP NSR enabled cannot act as GR restarter.

Step

Command

Remarks

RIP NSR enabled for a RIP process takes effect only on that

With the GR feature, the restarting router (known as the GR restarter) can notify the event to its GR capable neighbors. G R capable neighb ors (known as GR helpers) maintain the ir adjacencies with the router within a GR interval. During this process, the FIB table of the router does not change. After the restart, the router contacts its neighbors to retrieve its FIB.

By default, a RIP-enabled device acts as the GR helper. Perform this task on the GR restarter.

To configure GR on the GR restarter:

1. Enter system view.

2. Enter RIP view.

3. Enable GR for RIP.

interval.

Enabling RIP NSR

Nonstop Routing (N SR) allows the device to back up the routing information from the acti ve RIP process to the standb y RIP process. After an active/st andby switchover, NSR can complete rout e regeneration without tearing down adjacencies or impacting forwarding services.

NSR does not require the cooperation of neighboring devices to recover routing information, and it is typically used more often than GR.

system-view rip

[ process-id ] [

vpn-instance-name ]

graceful-restart

graceful-restart interv al

vpn-instance

interval

N/A

By default, RIP GR is disabled.

seconds.

To enable RIP NSR:

1. Enter system view.

2. Enter RIP view.

3. Enable RIP NSR.

system-view rip

[ process-id ] [

vpn-instance-name ]

non-stop-routing

Configuring BFD for RIP

RIP detects route failures b y periodically sending requests. If it receives no response for a route within a certain tim e, RIP consid ers the r oute unre achabl e. To speed up convergence, perf orm this

vpn-instance

N/A

By default, RIP NSR is disabled.

process. As a best practice, enable RIP NSR for each process if multiple RIP processes exist.

•

Step

Command

Remarks

system-view

onfigure the source IP

address of BFD echo

is not

By default, BFD for RIP is

Step

Command

Remarks

system-view

onfigure the source IP

address of BFD echo

BFD echo

rip bfd enable destination

By default, BFD for RIP is

task to enable BFD for RIP. For mor e information about BFD, see High Availability Configuration Guide.

RIP supports the following BFD detection modes:

Single-hop echo detection—Detection mode for a direct neighbor. In this mode, a BFD

session is established only when the directly connected neighbor has route information to send.

Single-hop echo detection for a specific destination—In this mode, a BFD session is

established to the specified RIP neighbor when RIP is enabled on the local interface.

Bidirectional control detection—Detection mode for an indirect neighbor. In this mode, a

BFD session is established only when both ends have routes to send and BFD is enabled on the receiving interface.

Configuring single-hop echo detection (for a direct l y connected RIP neighbor)

1. Enter system view.

2. C

packets.

3. Enter interface view.

4. Enable BFD for RIP.

bfd echo-source-ip

interface

interface-number

rip bfd enable

interface-type

ip-address

N/A By default, the source IP address

of BFD echo packets configured.

N/A

disabled.

Configuring single-hop echo detection (for a specifi c destination)

When a unidirectional link occurs between the local device and a specific neighbor, BFD can detect the failure. The local device will not receive or send any RIP packets through the interface connected to the neighbor to impr ove c onverg enc e s pe ed. When the link recovers , the i nter f ac e can s end RIP packets again.

This feature applies to RIP neighbors that are directly connected. To configure BFD for RIP (single hop echo detection for a specific destination):

1. Enter system view.

2. C

packets.

3. Enter interface view.

4. Enable BFD for RIP.

bfd echo-source-ip

interface

interface-number

ip-address

interface-type

ip-address

N/A By default, no source IP address

is configured for packets.

N/A

disabled.

Step

Command

Remarks

By default, RIP does not unicast

undo peer

immediately, executing the

Enable BFD on the RIP

By default, BFD is disabled on a

•

Router A Router B

Router E

Backup nexthop

Router C

Nexthop

: Router D

Configuring bidirectional control detection

1. Enter system view.

2. Enter RIP view.

3. Specify a RIP neighbor.

4. Enter interface view.

interface.

system-view rip

vpn-instance-name ]

peer

interface

interface-number

rip bfd enable

Configuring RIP FRR

A link or router failure on a path can cause pack et loss and even routing lo op until RIP completes routing convergence based on the new network topology . FRR enables fast rerouting to minimize the impact of link or node failures.

[ process-id ] [

ip-address

interface-type

vpn-instance

N/A

updates to any peer. Because the

command does not remove the neighbor relationship

command cannot bring down the BFD session immediately.

N/A

RIP interface.

Figure 6 Network diagram for RIP FRR

As shown in Figure 6, configure FRR on Router B by using a routing policy to specify a backup next hop. When the primary link fails, RIP directs packets to the backup next hop. At the same time, RIP calculates the shortest path based on the new network topology, and forwards packets over that path after network convergence.

Configuration restrictions and guidelines

RIP FRR takes effect only for RIP routes learned from directly connected neighbors. RIP FRR is available only when the state of primary link (with Layer 3 interfaces staying up)

changes from bidirectional to unidirectional or down.

Equal-cost routes do not support RIP FRR.

Step

Command

Remarks

Step

Command

Remarks

Configure the source IP address of BFD echo

of BFD echo packets is not

High Availability

detect bfd

Task

Command

Display RIP current status and configuration

Configuration prerequisites

You must specify a next hop by using the apply fast-reroute backup-interface command in a routing policy and ref erence the routing policy for FRR. For more inf ormation about rout ing policy configuration, see "Configuring routing policies."

Configuring RIP FRR

1. Enter system view.

2. Enter RIP view.

3. Configure RIP FRR.

system-view rip

[ process-id ] [

vpn-instance-name ]

fast-reroute route-policy

route-policy-name

Enabling BFD for RIP FRR

By default, RIP FRR does not use BFD to detect primary link failures. T o speed up RIP convergence, enable BFD single-hop echo detection for RIP FRR to detect pr imary link failures.

To configure BFD for RIP FRR:

1. Enter system view.

packets.

system-view

bfd echo-source-ip

vpn-instance

ip-address

N/A

By default, RIP FRR is disabled.

N/A By default, the source IP address

configured. The source IP address cannot be

on the same network segment as any local interface's IP address.

For more information about this command, see Command Reference.

3. Enter interface view.

4. Enable BFD for RIP FRR.

Displaying and maintaining RIP

Execute display commands in an y view and exec ute reset commands in user view.

information.

Display active routes in the RIP database.

Display RIP GR information.

interface

interface-number

rip primary-pathecho

interface-type

display rip

{ mask-length | mask } ]

display rip

N/A

By default, BFD for RIP FRR is disabled.

[ process-id ]

process-id

[ process-id ]

database

graceful-restart

[ ip-address

Task

Command

display rip

non-stop-routing

Vlan-int

102

2.1.1.1/24

Vlan-int100

1.1

.1.2

/24

Vlan-

int102

10.1.1.2

/24

Vlan

-int100

1.1.1.1/24

Vlan-

int101

10.2.1.1/24

Vlan-

int

101

.1.1

.1/

Switch A Switch B

Display RIP interface information.

Display neighbor information for a RIP process.

display rip

interface-number ]

display rip

interface-number ]

Display RIP NSR information.

display rip

Display routing information for a RIP process.

{ mask-length | mask } [

statistics

Reset a RIP process. Clear the statistics for a RIP process.

reset rip reset rip

RIP configuration examples

Configuring basic RIP

Network requirements

As shown in Figure 7, enable RIPv2 on all interfaces on Switch A and Switch B. Conf igure S witch B to not advertise route 10.2.1.0/24 to Switch A, and to accept only route 2.1.1.0/24 from Switch A.

Figure 7 Network diagram

process-id

[ process-id ]

process-id

]

process-id process-id

interface [

neighbor

route

verbose

process statistics

interface-type

[ interface-type

[ ip-address

peer

] |

ip-address |

Configuration procedure

1. Configure IP addresses for interfaces. (Details not shown.)

2. Configure basic RIP by using either of the following methods:

(Method 1) # Enable RIP on the specified networks on Switch A.

<SwitchA> system-view [SwitchA] rip [SwitchA-rip-1] network 1.0.0.0 [SwitchA-rip-1] network 2.0.0.0 [SwitchA-rip-1] network 3.0.0.0 [SwitchA-rip-1] quit

(Method 2) # Enable RIP on the specified interfaces on Switch B.

<SwitchB> system-view [SwitchB] rip [SwitchB-rip-1] quit [SwitchB] interface vlan-interface 100 [SwitchB-Vlan-interface100] rip 1 enable [SwitchB-Vlan-interface100] quit [SwitchB] interface vlan-interface 101

[SwitchB-Vlan-interface101] rip 1 enable [SwitchB-Vlan-interface101] quit [SwitchB] interface vlan-interface 102 [SwitchB-Vlan-interface102] rip 1 enable [SwitchB-Vlan-interface102] quit

# Display the RIP routing table of Switch A.

[SwitchA] display rip 1 route Route Flags: R - RIP, T - TRIP P - Permanent, A - Aging, S - Suppre ssed, G - Garbage-collect D - Direct, O - Optimal, F - Flush to RIB

--------------------------------------------------------------------------- Peer 1.1.1.2 on Vlan-interface100 Destination/Mask Nexthop Cost Tag Flags Sec

10.0.0.0/8 1.1.1.2 1 0 RAOF 11 Local route Destination/Mask Nexthop Cost Tag Flags Sec

1.1.1.0/24 0.0.0.0 0 0 RDOF -

2.1.1.0/24 0.0.0.0 0 0 RDOF -

3.1.1.0/24 0.0.0.0 0 0 RDOF -

The output shows that RIPv1 uses a natural mask.

3. Configure a RIP version: # Configure RIPv2 on Switch A.

[SwitchA] rip [SwitchA-rip-1] version 2 [SwitchA-rip-1] undo summary [SwitchA-rip-1] quit

# Configure RIPv2 on Switch B.

[SwitchB] rip [SwitchB-rip-1] version 2 [SwitchB-rip-1] undo summary [SwitchB-rip-1] quit

# Display the RIP routing table on Switch A.

[SwitchA] display rip 1 route Route Flags: R - RIP, T - TRIP P - Permanent, A - Aging, S - Suppre ssed, G - Garbage-collect D - Direct, O - Optimal, F - Flush to RIB

----------------------------------------------------------------------------

Peer 1.1.1.2 on Vlan-interface100 Destination/Mask Nexthop Cost Tag Flags Sec

10.0.0.0/8 1.1.1.2 1 0 RAOF 50

10.2.1.0/24 1.1.1.2 1 0 RAOF 16

10.1.1.0/24 1.1.1.2 1 0 RAOF 16 Local route Destina tion/Mask Nexthop Cost Tag Flags Sec

1.1.1.0/24 0.0.0.0 0 0 RDOF -

2.1.1.0/24 0.0.0.0 0 0 RDOF -

3.1.1.0/24 0.0.0.0 0 0 RDOF -

NOTE:

After RIPv2 is configured, RIPv1 routes might still exist in the routing table until they are aged out.

The output shows that RIPv2 uses classless subnet masks.

# Display the RIP routing table on Switch B.

[SwitchB] display rip 1 route Route Flags: R - RIP, T - TRIP P - Permanent, A - Aging, S - Suppre ssed, G - Garbage-collect D - Direct, O - Optimal, F - Flush to RIB

--------------------------------------------------------------------------- Peer 1.1.1.1 on Vlan-interface100 Destination/Mask Nexthop Cost Tag Flags Sec

2.1.1.0/24 192.168.1.3 1 0 RAOF 19

3.1.1.0/24 192.168.1.3 1 0 RAOF 19 Local route Destination/Mask Nexthop Cost Tag Flags Sec

1.1.1.0/24 0.0.0.0 0 0 RDOF -

10.1.1.0/24 0.0.0.0 0 0 RDOF -

10.2.1.0/24 0.0.0.0 0 0 RDOF -

4. Configure route filtering: # Reference IP prefix lists on Switch B to filter received and redistributed routes.

[SwitchB] ip pr efix-list aaa index 10 permit 2.1 .1. 0 24 [SwitchB] ip pr efix-list bbb index 10 permit 10.1 .1.0 24 [SwitchB] ip pr efix-list bbb index 11 permit 0.0 .0. 0 0 less-equal 32 [SwitchB] ri p 1 [SwitchB-rip-1] filter-policy prefix -list aaa impo rt [SwitchB-rip-1] filter-policy prefix -list bbb export [SwitchB-rip-1] quit

# Display the RIP routing table on Switch A.

[SwitchA] display rip 100 route Route Flags: R - RIP, T - TRIP P - Permanent, A - Aging, S - Suppre ssed, G - Garbage-collect

--------------------------------------------------------------------------- Peer 1.1.1.2 on Vlan-interface100 Destination/Mask Nexthop Cost Tag Flags Sec

10.1.1.0/24 1.1.1.2 1 0 R AO F 19 Local route Destination/Mask Nexthop Cost Tag Flags Sec

1.1.1.0/24 0.0.0.0 0 0 RDOF -

2.1.1.0 /24 0.0.0.0 0 0 RDOF -

3.1.1.0/24 0.0.0.0 0 0 RDOF -

# Display the RIP routing table on Switch B.

[SwitchB] display rip 1 route Route Flags: R - RIP, T - TRIP P - Permanent, A - Aging, S - Suppre ssed, G - Garbage-collect D - Direct, O - Optimal, F - Flush to RIB

----------------------------------------------------------------------------

Eth1/1

Vlan-int100

11.1.1.2/24

Vlan-int200

12.3.1.2/24

Vlan-int200 12

.3.1.1/24

Vlan-int400

16.4.1.1/24

Vlan

-int101

10.2.1.1/24

Vlan-int100

11.1.1.1/24

Switch A

Switch B

Switch C

RIP 100 RIP 200

Peer 1.1.1.1 on Vlan-interface100 Destina tion/Mask Nexthop Cost Tag Flags Sec

2.1.1.0/24 1.1.1.3 1 0 RAOF 19 Local route Destination/Mask Nexthop Cost Tag Flags Sec

1.1.1.0/24 0.0.0.0 0 0 RDOF -

10.1.1.0/24 0.0.0.0 0 0 RDOF -

10.2.1.0/24 0.0.0.0 0 0 RDOF -

Configuring RI P route redistribution

Network requirements

As shown in Figure 8, Swit ch B communicates with Switc h A through RIP 100 and with Switch C through RIP 200.

Configure RIP 200 to redistribute direct routes and routes from RIP 100 on Switch B so Switch C can learn routes destined for 10.2.1.0/24 and 11.1.1.0/24. Switch A cannot learn routes dest ined for

12.3.1.0/24 and 16.4.1.0/24 .

Figure 8 Network diagram

Configuration procedure

1. Configure IP addresses for interfaces. (Details not shown.)

2. Configure basic RIP:

# Enable RIP 100, and configure RIPv2 on Switch A.

<SwitchA> sy stem-view [SwitchA] ri p 100 [SwitchA-rip-100] network 10.0.0.0 [SwitchA-rip-100] network 11.0.0.0 [SwitchA-rip-100] version 2 [SwitchA-rip-100] undo summary [SwitchA-rip-100] quit

# Enable RIP 100 and RIP 200, and configure RIPv2 on Switch B.

<SwitchB> sy stem-view [SwitchB] ri p 100 [SwitchB-rip-100] network 11.0.0.0 [SwitchB-rip-100] version 2 [SwitchB-rip-100] undo summary [SwitchB-rip-100] quit [SwitchB] rip 200 [SwitchB-rip-200] network 12.0.0.0 [SwitchB-rip-200] version 2 [SwitchB-rip-200] undo summary

[SwitchB-rip-200] quit

# Enable RIP 200, and configure RIPv2 on Switch C.

<SwitchC> sy stem-view [SwitchC] ri p 200 [SwitchC-rip-200] network 12.0.0.0 [SwitchC-rip-200] network 16.0.0.0 [SwitchC-rip-200] version 2 [SwitchC-rip-200] undo summary [SwitchC-rip-200] quit

# Display the IP routing table on Switch C.

[SwitchC] display ip routing-table

Destinations : 13 Routes : 13

Destination/Mask Proto Pre Cost NextHop Interface

0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

12.3.1.0/24 Direct 0 0 12.3.1.2 Vlan200

12.3.1.0/32 Direct 0 0 12.3.1.2 Vlan200

12.3.1.2/32 Direct 0 0 127.0.0.1 InLoop0

12.3.1.255/32 Direct 0 0 12.3.1.2 Vlan200

16.4.1.0/24 Direct 0 0 16.4.1.1 Vlan400

16.4.1.0/32 Direct 0 0 16.4.1.1 Vlan400

16.4.1.1/32 Direct 0 0 127.0.0.1 InLoop0

16.4.1.255/32 Direct 0 0 16.4.1.1 Vlan400

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

3. Configure route redistribution: # Configure RIP 200 to redistribute routes from RIP 100 and direct routes on Switch B.

[SwitchB] ri p 200 [SwitchB-rip-200] import-route rip 100 [SwitchB-rip-200] import-route direct [SwitchB-rip-200] quit

# Display the IP routing table on Switch C.

[SwitchC] display ip routing-table

Destinations : 15 Routes : 15

Destination/Mask Proto Pre Cost NextHop Interface

0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

10.2.1.0/24 RIP 100 1 12.3.1.1 Vlan200

11.1.1.0/2 4 RIP 100 1 12.3.1.1 Vlan200

12.3.1.0/24 Direct 0 0 12.3.1.2 Vlan200

12.3.1.0/32 Direct 0 0 12.3.1.2 Vlan200

12.3.1.2/32 Direct 0 0 127.0.0.1 InLoop0

12.3.1.255/32 Direct 0 0 12.3.1.2 Vlan200

16.4.1.0/24 Direct 0 0 16.4.1.1 Vlan400

Switch B

Switch C

Switch A

Switch D Switch E

Vlan-int100

1.1.1.1/24

Vlan-int100

1.1.1.2/24

Vlan-int200

1.1.2.1/24 Vlan-int200

1.1.2.2/24

Vlan-int400

1.1.3.1/24

Vlan-int300

1.1.4.1/24

Vlan-int400

1.1.3.2/24

Vlan-int300

1.1.4.2/24

Vlan-int500

1.1.5.1/24

Vlan-int500

1.1.5.2/24

16.4.1.0/32 Direct 0 0 16.4.1.1 Vlan400

16.4.1.1/32 Direct 0 0 127.0.0.1 InLoop0

16.4.1.255/32 Direct 0 0 16.4.1.1 Vlan400

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

Configuring an add i tional metric for a R IP interface

Network requirements

As shown in Figure 9, run RIPv2 on all the interfaces of Switch A, Switch B, Switch C, Switch D, and Switch E.

Switch A has two links to Switch D. The link from Switch B to Switch D is more stable than that from Switch C t o Switch D. Conf igure an additional m etric for RIP routes received f rom VLAN-interface 200 on Switch A so Switch A prefers route 1.1.5.0/24 learned from Switch B.

Figure 9 Network diagram

Configuration procedure

1. Configure IP addresses for interfaces. (Details not shown.)

2. Configure basic RIP:

# Configure Switch A.

<SwitchA> system-view [SwitchA] rip 1 [SwitchA-rip-1] network 1.0.0.0 [SwitchA-rip-1] version 2 [SwitchA-rip-1] undo summary [SwitchA-rip-1] quit

# Configure Switch B.

<SwitchB> sy stem-view [SwitchB] rip 1 [SwitchB-rip-1] network 1.0.0.0 [SwitchB-rip-1] version 2 [SwitchB-rip-1] undo summary

# Configure Switch C.

<SwitchC> sy stem-view [SwitchB] rip 1 [SwitchC-rip-1] network 1.0.0.0 [SwitchC-rip-1] version 2

[SwitchC-rip-1] undo summary

# Configure Switch D.

<SwitchD> sy stem-view [SwitchD] rip 1 [SwitchD-rip-1] network 1.0.0.0 [SwitchD-rip-1] version 2 [SwitchD-rip-1] undo summary

# Configure Switch E.

<SwitchE> sy stem-view [SwitchE] rip 1 [SwitchE-rip-1] network 1.0.0.0 [SwitchE-rip-1] version 2 [SwitchE-rip-1] undo summary

# Display all active routes in the RIP database on Switch A.

[SwitchA] display rip 1 database

1.0.0.0/8, auto-summary

1.1.1.0/24, cost 0, ne xt hop 1.1.1.1, RIP-interface

1.1.2.0/24, cost 0, ne xt hop 1.1.2.1, RIP-interface

1.1.3.0/24, cost 1, ne xt hop 1.1.1.2

1.1.4.0/24, cost 1, ne xt hop 1.1.2.2

1.1.5.0/24, cost 2, ne xt hop 1.1.1.2

1.1.5.0/24, cost 2, ne xt hop 1.1.2.2

The output shows two RIP routes destined for network 1.1.5.0/24, with the next hops as Switch B (1.1.1.2) and Switch C (1.1.2.2), and with the same cost of 2.

3. Configure an additional metric for a RIP interface: # Configure an inbound additional metric of 3 for RIP-enabled interface VLAN-interface 200 on

Switch A.

[SwitchA] interface vlan-interface 200 [SwitchA-Vlan-interface200] rip metricin 3

# Display all active routes in the RIP database on Switch A.

[SwitchA-Vlan-interface200] display rip 1 database

1.0.0.0/8, auto-summary

1.1.1.0/24, cost 0, ne xt hop 1.1.1.1, RIP-interface

1.1.2.0/24, cost 0, ne xt hop 1.1.2.1, RIP-interface

1.1.3.0/24, cost 1, ne xt hop 1.1.1.2

1.1.4.0/24, cost 2, nexthop 1.1.1.2

1.1.5.0/24, cost 2, ne xt hop 1.1.1.2

The output shows that only one RIP route reaches network 1.1.5.0/24, with the next hop as Switch B (1.1.1.2) and a cost of 2.

Configuring RIP to advertise a summary route

Network requirements

As shown in Figure 10, Sw itch A and Switch B run OSPF, Switch D runs RIP, and Switch C runs OSPF and RIP. Configure RIP to redistribute OSPF routes on Switch C so Switch D can learn routes destined for networks 10.1.1.0/24, 10.2.1.0/24, 10.5.1.0/24, and 10.6.1.0/24.

To reduce the routin g tabl e size o f Swit ch D, configure route summarization on Switch C to advertise only the summary route 10.0.0.0/8 to Switch D.

Switch A

Vlan-int100

10.2.1.2/24

Switch C

Vlan-int100

10.2.1.1/24

Vlan-int300

11.3.1.2/24

Switch D

RIP

OSPF

Switch B

Vlan-int200

10.1.1.2/24

Vlan-int200

10.1.1.1/24

Vlan-int300

11.3.1.1/24

Vlan-int400

11.4.1.2/24

Vlan-int500

10.6.1.2/24

Vlan-int600

10.5.1.2/24

Figure 10 Network diagram

Configuration procedure

1. Configure IP addresses for interfaces. (Details not shown.)

2. Configure basic OSPF:

# Configure Switch A.

<SwitchA> sy stem-view [SwitchA] ospf [SwitchA-ospf-1] area 0 [SwitchA-ospf-1-area-0.0.0.0] network 10.5.1.0 0.0.0.255 [SwitchA-ospf-1-area-0.0.0.0] network 10.2.1.0 0.0.0.255 [SwitchA-ospf-1-area-0.0.0.0] quit

# Configure Switch B.

<SwitchB> sy stem-view [SwitchB] ospf [SwitchB-ospf-1] area 0 [SwitchB-ospf-1-area-0.0.0 .0] network 10.1.1.0 0.0.0.255 [SwitchB-ospf-1-area-0.0.0 .0] network 10.6.1.0 0.0.0.255 [SwitchB-ospf-1-area-0.0.0.0] quit

# Configure Switch C.

<SwitchC> sy stem-view [SwitchC] ospf [SwitchC-ospf-1] area 0 [SwitchC-ospf-1-area-0.0.0 .0] network 10.1.1.0 0.0.0.255 [SwitchC-ospf-1-area-0.0.0.0] network 10.2.1.0 0.0.0.255 [SwitchC-ospf-1-area-0.0.0.0] quit [SwitchC-ospf-1] quit

3. Configure basic RIP: # Configure Switch C.

[SwitchC] rip 1 [SwitchC-rip-1] network 11.3.1.0 [SwitchC-rip-1] version 2 [SwitchC-rip-1] undo summary

# Configure Switch D.

<SwitchD> sy stem-view [SwitchD] rip 1

[SwitchD-rip-1] network 11.0.0.0 [SwitchD-rip-1] version 2 [SwitchD-rip-1] undo summary [SwitchD-rip-1] quit

# Configure RIP to redistribute routes from OSPF process 1 and direct routes on Switch C.

[SwitchC-rip-1] import-route direct [SwitchC-rip-1] import-route ospf 1 [SwitchC-rip-1] quit

# Display the IP routing table on Switch D.

[SwitchD] display ip routing-table

Destinations : 15 Routes : 15

Destination/Mask Proto Pre Cost NextHop Interface

0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

10.1.1.0/2 4 RIP 100 1 11.3.1.1 Vlan300

10.2.1.0/24 RIP 100 1 11.3.1.1 Vlan300

10.5.1.0/2 4 RIP 100 1 11.3.1.1 Vlan300

10.6.1.0/2 4 RIP 100 1 11.3.1.1 Vlan300

11.3.1.0/24 Direct 0 0 11.3.1.2 Vlan300

11.3.1.0/32 Direct 0 0 11.3.1.2 Vlan300

11.3.1.2/32 Direct 0 0 127.0.0.1 InLoop0

11.4.1.0/24 Direct 0 0 11.4. 1.2 Vlan400

11.4.1.0/32 Direct 0 0 11.4.1.2 Vlan400

11.4.1.2/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

127.255.255.2 55/32 Direct 0 0 127.0.0.1 InLoop0

4. Configure route summarization: # Configure route summarization on Switch C and advertise only the summary route 10.0.0.0/8.

[SwitchC] inte rface vlan-interface 300 [SwitchC-Vlan-interface300] rip summary-address 10.0.0.0 8

# Display the IP routing table on Switch D.

[SwitchD] display ip routing-table

Destinations : 12 Routes : 12

Destination/Mask Proto Pre Cost NextHop Interface

0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

10.0.0.0/8 RIP 100 1 11.3.1.1 Vlan300

11.3.1.0/24 Direct 0 0 11.3.1.2 Vlan300

11.3.1.0/32 Direct 0 0 11.3.1.2 Vlan300

11.3.1.2/32 Direct 0 0 127.0.0.1 InLoop0

11.4.1.0/24 Direct 0 0 11.4.1.2 Vlan400

11.4.1.0/32 Direct 0 0 11.4.1.2 Vlan400

11.4.1.2/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

•

Vlan-int100

192.1.1.1/24

Vlan-int100

192.1.1.3/24

Vlan-int100

192.1.1.2/24

GR helper GR helper

GR restarter

Switch A

Switch CSwitch B

Router ID: 1.1.1.1

Router ID: 2.2.2.2

Router ID: 3.3.3.3

127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

127.255.255.2 55/32 Direct 0 0 127.0.0.1 InLoop0

Configuring RI P GR

Network requirements

As shown in Figure 11, Switch A, Switch B, and Switch C all run RIPv2.

Enable GR on Switch A. Switch A acts as the GR restarter. Switch B and Switch C act as GR helpers to synchronize their routing tables with Switc h A by

using GR.

Figure 11 Network diagram

Configuration procedure

1. Configure IP addresses and subnet masks for interfaces on the switches. (Details not shown.)

2. Configure RIPv2 on the switches to ensure the following: (Details not shown.)

 Switch A, Switch B, and Switch C can communicate with each other at Layer 3.  Dynamic route update can be implemented among them with RIPv2.

3. Enable RIP GR on Switch A.

<SwitchA> sy stem-view [SwitchA] rip [SwitchA-rip-1] graceful-restart

Verifying the configuration

# Restart RIP process 1 on Switch A.

[SwitchA-rip-1] return <SwitchA> re set rip 1 process Reset RIP process? [Y/N]:y

# Display GR status on Switch A.

<SwitchA> display rip graceful-restart RIP process: 1 Graceful Restart capability : Enabled Current GR state : Normal Graceful Restart period : 60 seconds Graceful Restart remaining time : 0 seconds

Loop 0

22.22.22.22/32

Vlan-int100

12.12.12.1/24 Vlan-int100

12.12.12.2/24

Vlan-int200

14.14.14.2/24

Vlan-int200

14.14.14.1/24

Loop 0

44.44.44.44/32

Switch S

Switch A

Switch B

Configuring RI P N S R

Network requirements

As shown in Figure 12, Switch A, Switch B, and Switch S all run RIPv2. Enable RIP NSR on Switch S to ensure correct routing when an active/standby switchover occurs on

Switch S.

Figure 12 Network diagram

Configuration procedure

1. Configure IP addresses and subnet masks for interfaces on the switches. (Details not shown.)

2. Configure RIPv2 on the switches to ensure the following: (Details not shown.)

 Switch A, Switch B, and Switch S can communicate with each other at Layer 3.  Dynamic route update can be implemented among them with RIPv2.

3. Enable RIP NSR on Switch S.

<SwitchS> sy stem-view [SwitchS] ri p 100 [SwitchS-rip-100] non-stop-routing [SwitchS-rip-100] quit

Verifying the configuration

# Perform an active/standby switchover on Switch S .

[SwitchS] placement reoptimize Predicted ch anges to the placeme nt Program Current location New location

--------------------------------------------------------------------lb 0/0 0/0 lsm 0/0 0/0 slsp 0/0 0/0 rib6 0/0 0/0 routepolic y 0/0 0/0 rib 0/0 0/0 staticroute6 0/0 0/0 staticroute 0/0 0/0 ospf 0/0 1/0 Continue? [y /n]:y Re-optimization of the placement start . You will be notified on completion Re-optimizati on of the placement complete. Use ' display placement' to view the new

placement

# Display neighbor information and route information on Switch A.

[SwitchA] display rip 1 neighbor Neighbor Addre ss: 12.12.12.2 Interface : Vlan-interface200

Version : RIPv2 Last update: 00h00m13s Relay nbr : No BFD session: None Bad packets: 0 Bad routes : 0 [SwitchA] display rip 1 route Route Flags: R - RIP, T - TRIP P - Permanent, A - Aging, S - Suppre ssed, G - Garbage-collect D - Direct, O - Optimal, F - Flush to RIB

--------------------------------------------------------------------------- Peer 12.12.12.2 on Vlan-interface200 Destination/Mask Nexthop Cost Tag Flags Sec

14.0.0.0/8 12.12.12. 2 1 0 RAOF 16

44.0.0.0/8 12.12.12.2 2 0 RAOF 16 Local route Destination/Mask Nexthop Cost Tag Flags Sec

12.12.12.0/24 0.0.0.0 0 0 RDOF -

22.22.22.22/32 0.0.0.0 0 0 RDOF -

# Display neighbor information and route information on Switch B.

[SwitchB] display rip 1 neighbor Neighbor Addre ss: 14.14.14.2 Interface : Vlan-interface200 Version : RIPv2 Last update: 00h00m32s Relay nbr : No BFD session: None Bad packets: 0 Bad routes : 0 [SwitchB] display rip 1 route Route Flags: R - RIP, T - TRIP P - Permanent, A - Aging, S - Suppre ssed, G - Garbage-collect D - Direct, O - Optimal, F - Flush to RIB

--------------------------------------------------------------------------- Peer 14.14.14.2 on Vlan-interface200 Destination/Mask Nexthop Cost Tag Flags Sec

12.0.0.0/8 14.14.14.2 1 0 RAOF 1

22.0.0.0/8 14.14.14.2 2 0 RAOF 1 Local route Destination/Mask Nexthop Cost Tag Flags Sec

44.44.44.44/32 0.0.0.0 0 0 RDOF -

14.14.14.0/24 0.0.0.0 0 0 RDOF -

The output shows that the neighbor and route information on Switch A and Switch B keep unchanged during the active/standby switchover on Switch S. The traffic from Switch A to Switch B has not been impacted.

Configuring BFD for RIP (single-ho p echo detection for a directly connected neighbor)

Network requirements

As shown in Figure 13, VLAN-interface 100 of Switch A and Switch C runs RIP process 1. VLAN-interface 200 of Switch A runs RIP process 2. VLAN-interface 300 of Switch C and VLAN-interface 200 and VLAN-interface 300 of Switch B run RIP process 1.

•

Vlan

-int100

192.168.1.1/24

BFD

Switch A

Switch C

Vlan-int100

192.168.1.2/24

L2 switch

Vlan-int300

192.168.3.1/24

Vlan-int300

192.168.3.2/24

Vlan-int200

192.168.2.2/24

Vlan-int200

192.168.2.1/24

Switch B

Configure a static route destined for 100.1.1.1/24 and enable static route redistribution into RIP

on Switch C. This allows Switch A to learn two routes destined for 100.1.1.1/24 through VLAN-interface 100 and VLAN-interface 200 respectively, and uses the one through VLAN-interface 100.

Enable BFD for RIP on VLAN-interface 100 of Switch A. When the link over VLAN-interface 100

fails, BFD can quickly detect the failure and notify RIP. RIP deletes the neighbor relationship and route information learned on VLAN-interface 100, and uses the route destined for 100.1.1.1 24 through VLAN-interf ac e 200.

Figure 13 Network diagram

Configuration procedure

1. Configure IP addresses for interfaces. (Details not shown.)

2. Configure basic RIP:

# Configure Switch A.

<SwitchA> sy stem-view [SwitchA] rip 1 [SwitchA-rip-1] version 2 [SwitchA-rip-1] undo summary [SwitchA-rip-1] network 192.168.1.0 [SwitchA-rip-1] quit [SwitchA] interface vlan-interface 100 [SwitchA-Vlan-interface100] rip bfd enable [SwitchA-Vlan-interface100] quit [SwitchA] rip 2 [SwitchA-rip-2] version 2 [SwitchA-rip-2] undo summary [SwitchA-rip-2] network 192.168.2.0 [SwitchA-rip-2] quit

# Configure Switch B.

<SwitchB> sy stem-view [SwitchB] rip 1 [SwitchB-rip-1] version 2 [SwitchB-rip-1] undo summary [SwitchB-rip-1] network 192.168.2.0 [SwitchB-rip-1] network 192.168.3.0 [SwitchB-rip-1] quit

# Configure Switch C.

<SwitchC> sy stem-view [SwitchC] rip 1 [SwitchC-rip-1] version 2 [SwitchC-rip-1] undo summary [SwitchC-rip-1] netwo rk 192.168.1.0 [SwitchC-rip-1] netwo rk 192.168.3.0 [SwitchC-rip-1] import-route static [SwitchC-rip-1] quit

3. Configure BFD parameters on VLAN-interface 100 of Switch A.

[SwitchA] bf d echo-source-ip 11.11.11.11 [SwitchA] interface vlan-interface 100 [SwitchA-Vlan-interface100] bfd min-transmit-interval 500 [SwitchA-Vlan-interface100] bfd min-receive-interval 500 [SwitchA-Vlan-interface100] bfd detect-multiplier 7 [SwitchA-Vlan-interface100] quit [SwitchA] quit

4. Configure a static route on Switch C.

[SwitchC] ip route-static 120.1.1.1 24 null 0

Verifying the configuration

# Display the BFD session information on Switch A.

<SwitchA> display bfd session

Total Session Nu m: 1 Up Session Num: 1 Init Mode: Ac tive

IPv4 Session Working Under Echo Mode:

LD SourceAddr DestAddr State Holdtime Interface 4 19 2.168.1.1 192.168.1. 2 Up 2000ms Vlan100

# Display RIP routes destined for 120.1.1.0/24 on Switch A.

<SwitchA> display ip routing-table 120.1.1.0 24

Summary coun t : 1

Destination/Mask Proto Pre Cost NextHop Interface

120.1.1.0/24 RIP 100 1 192.168.1.2 Vlan-interface100

The output shows that Switch A communicates with Switch C through VLAN-interface 100. Then the link over VLAN-interface 100 fails.

# Display RIP routes destined for 120.1.1.0/24 on Switch A.

<SwitchA> display ip routing-table 120.1.1.0 24

Summary coun t : 1

Destination/Mask Proto Pre Cost NextHop Interface

120.1.1.0/24 RIP 100 1 192.168.2.2 Vlan-interface200

The output shows that Switch A communicates with Switch C through VLAN-interface 200.

•

Switch A Switch C

Vlan-int200

192.168.3.1/24

Vlan-int200

192.168.3.2/24

Vlan-int100

192.168.2.2/24

Vlan-int100

192.168.2.1/24

Switch B

RIP packets BFD session

Fault

Configuring BFD for RIP (single hop echo detection for a specific destination)

Network requirements

As shown in Figure 14, VLAN-interface 100 of Switch A and Switch B runs RIP process 1. VLAN-interface 200 of Switch B and Switch C runs RIP process 1.

Configure a static route destined for 100.1.1.0/24 and enable static route redistribution into RIP

on both Switch A and Switch C. This allows Switch B to learn two routes destined for

100.1.1.0/24 through VLAN-interface 100 and VLAN-interface 200. The route redistributed from Switch A has a smaller cost than that redistributed from Switch C, so Switch B uses the route through VLAN-interface 200.

Enable BFD for RIP on VLAN-interface 100 of Switch A, and specify VLAN-interface 100 of

Switch B as the destination. When a unidirectional link occurs between Switch A and Switch B, BFD can quickly detect the link failure and notify RIP. Swit c h B then deletes the neighbor relationship and the route information learned on VLAN-interface 100. It does not receive or send any packets from VLAN-interface 100. When the route learned from Switch A ages out, Switch B uses the route destined for 100.1.1.1 24 through VLAN-interface 200.

Figure 14 Network diagram

Configuration procedure

1. Configure IP addresses for interfaces. (Details not shown.)

2. Configure basic RIP and enable BFD on the interfaces:

# Configure Switch A.

<SwitchA> system-view [SwitchA] rip 1 [SwitchA-rip-1] network 192.168.2.0 [SwitchA-rip-1] import-route static [SwitchA-rip-1] quit [SwitchA] interface vlan-interface 100 [SwitchA-Vlan-interface100] rip bfd enable destination 192.168.2.2 [SwitchA-Vlan-interface100] quit

# Configure Switch B.

<SwitchB> sy stem-view [SwitchB] rip 1 [SwitchB-rip-1] network 192.168.2.0

[SwitchB-rip-1] network 192.168.3.0 [SwitchB-rip-1] quit

# Configure Switch C.

<SwitchC> sy stem-view [SwitchC] rip 1 [SwitchC-rip-1] network 192.168.3.0 [SwitchC-rip-1 ] import-route static cost 3 [SwitchC-rip-1] quit

3. Configure BFD parameters on VLAN-interface 100 of Switch A.

[SwitchA] bfd echo-source-ip 11.11.11.11 [SwitchA] interface vlan-interface 100 [SwitchA-Vlan-interface100] bfd min-echo-receive-interval 500 [SwitchA-Vlan-interface100] return

4. Configure static routes: # Configure a static route on Switch A.

[SwitchA] ip route-static 100.1.1.0 24 null 0

# Configure a static route on Switch C.

[SwitchA] ip route-static 100.1.1.0 24 null 0

Verifying the configuration

# Display BFD session information on Switch A.

<SwitchA> display bfd session

Total Session Nu m: 1 Up Session Num: 1 Init Mode: Active

IPv4 session working under Echo mode:

LD SourceAddr DestAddr State Holdtime Interface 3 192.168.2.1 192.168 .2.2 Up 2000ms vlan100

# Display routes destined for 100.1.1.0/24 on Switch B.

<SwitchB> display ip routing-table 100.1. 1. 0 24 verbose

Summary Coun t : 1

Destination: 100.1.1.0/24 Protocol: RIP Process ID: 1 SubProtID: 0x1 Age: 00h02m47s Cost: 1 Preference: 100 IpPre: N/A QosLocalID: N/A Tag: 0 State: Active Adv OrigTblID: 0x0 OrigVrf: default-vrf TableID: 0x2 OrigAs: 0 NibID: 0x12000002 LastAs: 0 AttrID: 0xffffffff Neighbor: 19 2.168.2.1 Flags: 0x1008c OrigNextHop: 192 .168.2.1 Label: NULL RealNex tHop: 192.168.2. 1 BkLabel: NULL BkNextHop: N/A

•

Tunnel ID: Inva lid Interface: vlan-interface 100 BkTunnel ID: Inva lid BkInterface: N/A FtnIndex: 0x0 TrafficIndex: N/A Connector: N/A

# Display routes destined for 100.1.1.0/24 on Switch B when the link between Switch A and Switch B fails.

<SwitchB> display ip routing-table 100.1. 1. 0 24 verbose

Summary Coun t : 1

Destination: 100.1.1.0/24 Protocol: RIP Process ID: 1 SubProtID: 0x1 Age: 00h21m23s Cost: 4 Preference: 100 IpPre: N/A QosLocalID: N/A Tag: 0 State: Active Adv OrigTblID: 0x0 OrigVrf: default-vrf TableID: 0x2 OrigAs: 0 NibID: 0x12000002 LastAs: 0 AttrID: 0xffffffff Neighbor: 192.168.3.2 Flags: 0x1008c OrigNextHop: 192 .168.3.2 Label: NULL RealNex tHop: 192.168.3. 2 BkLabel: NULL BkNextHop: N/A Tunnel ID: Inva lid Interface: vlan-interface 200 BkTunnel ID: Inva lid BkInterface: N/A FtnIndex: 0x0 TrafficIndex: N/A Connector: N/A

Configuring BFD for RIP (bidirectional detection in BFD control packet mode)

Network requirements

As shown in Figure 15, VLAN-interface 100 of Switch A and VLAN-interface 200 of Switch C run RIP process 1.

VLAN-interface 300 of Switch A runs RIP process 2. VLAN-interface 400 of Switch C, and VLAN-interface 300 and VLAN-interface 400 of Switch D run RIP process 1.

Configure a static route destined for 100.1.1.0/24 on Switch A. Configure a static route destined for 101.1.1.0/24 on Switch C. Enable static route redistribution into RIP on Switch A and Switch C. This allows Switch A to

learn two routes destined for 100.1.1.0/24 through VLAN-interface 100 and VLAN-interface 300. It uses the route through VLAN-interface 100.

Enable BFD on VLAN-interface 100 of Switch A and VLAN-interface 200 of Switch C.

When the link over VLAN-interface 100 fails, BFD c an quick ly detect the link failur e and notif y RIP. RIP deletes the neighbor relationship and the route information received learned on VLAN-interface

100. It uses the route destined for 100.1.1.0/24 through VLAN-interface 300.

Device

Interface

IP address

100.1.1.0/24

101.1.1.0/24

Switch C

Switch A

Vlan-

int100

Vlan-int100

Switch B

Vlan-int200

BFD

Vlan-int200

Switch D

Vlan-int300

Vlan-int

400

Vlan

int400

Figure 15 Network diagram

Table 7 Interface and IP address assignment

Switch A VLAN-interface 300 192.168.3.1/24 Switch A VLAN-interface 100 192.168.1.1/24 Switch B VLAN-interface 100 192.168.1.2/24 Switch B VLAN-interface 200 192.168.2.1/24 Switch C VLAN-interface 200 192.168.2.2/24 Switch C VLAN-interface 400 192.168.4.2/24 Switch D VLAN-interface 300 192.168.3.2/24 Switch D VLAN-interface 400 192.168.4.1/24

Configuration procedure

1. Configure IP addresses for interfaces. (Details not shown.)

2. Configure basic RIP and enable static route redistribution into RIP so Switch A and Switch C

have routes to send to each other: # Configure Switch A.

<SwitchA> sy stem-view [SwitchA] rip 1 [SwitchA-rip-1] version 2 [SwitchA-rip-1] undo summary [SwitchA-rip-1] network 192.168.1.0 [SwitchA-rip-1] network 101.1.1.0 [SwitchA-rip-1] peer 192.168.2.2 [SwitchA-rip-1] undo validate-source-address [SwitchA-rip-1] import-route static [SwitchA-rip-1] quit [SwitchA] interface vlan-interface 100 [SwitchA-Vlan-interface100] rip bfd enable [SwitchA-Vlan-interface100] quit [SwitchA] rip 2 [SwitchA-rip-2] version 2

[SwitchA-rip-2] undo summary [SwitchA-rip-2] network 192.168.3.0 [SwitchA-rip-2] quit

# Configure Switch C.

<SwitchC> sy stem-view [SwitchC] rip 1 [SwitchC-rip-1] version 2 [SwitchC-rip-1] undo summary [SwitchC-rip-1] network 192.168.2.0 [SwitchC-rip-1] netwo rk 192.168.4.0 [SwitchC-rip-1] network 100.1.1.0 [SwitchC-rip-1] peer 192.168.1.1 [SwitchC-rip-1] undo validate-source-address [SwitchC-rip-1] import-route static [SwitchC-rip-1] quit [SwitchC] interface vlan-interface 200 [SwitchC-Vlan-interface200] rip bfd enable [SwitchC-Vlan-interface200] quit

# Configure Switch D.

<SwitchD> sy stem-view [SwitchD] rip 1 [SwitchD-rip-1] version 2 [SwitchD-rip-1] undo summary [SwitchD-rip-1] netwo rk 192.168.3.0 [SwitchD-rip-1] netwo rk 192.168.4.0

3. Configure BFD parameters: # Configure Switch A.

[SwitchA] bfd session init-mode active [SwitchA] interface vlan-inte rface 100 [SwitchA-Vlan-interface100] bfd min-transmit-interval 500 [SwitchA-Vlan-interface100] bfd min-receive-interval 500 [SwitchA-Vlan-interface100] bfd detect-multi plier 7 [SwitchA-Vlan-interface100] quit

# Configure Switch C.

[SwitchC] bfd session init-mode acti ve [SwitchC] interface vlan-interface 200 [SwitchC-Vlan-interface200] bfd min-transmit-interval 500 [SwitchC-Vlan-interface200] bfd min-receive-interval 500 [SwitchC-Vlan-interface200] bfd detect-multiplier 7 [SwitchC-Vlan-interface200] quit

4. Configure static routes: # Configure a static route to Switch C on Switch A.

[SwitchA] ip route-static 192.168.2.0 24 vlan-interface 100 192.168.1. 2 [SwitchA] quit

# Configure a static route to Switch A on Switch C.

[SwitchC] ip route-static 192.168.1.0 24 vlan-interf ace 200 192.168.2.1

Device

Interface

IP address

Switch A Switch B

Switch C

Loop0

Vlan-int100

Vlan-int200

Vlan-int100

Vlan-int101

Loop0

Link A

Link B

Verifying the configuration

# Display the BFD session information on Switch A.

<SwitchA> display bfd session

Total Session Nu m: 1 Up Session Num: 1 Init Mode: Active

IPv4 session working under Ctrl mode:

LD/RD Sou rceAddr DestAddr State Holdtime Interface 513/513 192.168.1.1 192.168.2.2 Up 1700ms vlan100

# Display RIP routes destined for 100.1.1.0/24 on Switch A.

<SwitchA> display ip routing-table 100.1. 1. 0 24

Summary coun t : 1

Destination/Mask Proto Pre Cost NextHop Interface

100.1.1.0/24 RIP 100 1 192.168.2.2 vlan-interface 100

The output shows that Switch A communicates with Switch C through VLAN-interface 100. Then the link over VLAN-interface 100 fails.

# Display RIP routes destined for 100.1.1.0/24 on Switch A.

<SwitchA> display ip routing-table 100.1.1.0 24

Summary coun t : 1

Destination/Mask Proto Pre Cost NextHop Interface

100.1.1.0/24 RIP 100 2 192.168.3.2 vlan-interface 300

The output shows that Switch A communicates with Switch C through VLAN-interface 300.

Configuring RI P FRR

Network requirements

As shown in Figure 1 6, Switch A, Switch B, and Switch C run RIP v2. Configure RIP FRR so that when Link A becomes unidirectional, services can be switched to Link B immediately.

Figure 16 Network diagram

Table 8 Interface and IP address assignment

Switch A VLAN-interface 100 12.12.12.1/24

Device

Interface

IP address

Switch A VLAN-interface 200 13.13.13.1/24 Switch A Loopback 0 1.1.1.1/32 Switch B VLAN-interface 101 24.24.24.4/24 Switch B VLAN-interface 200 13.13.13.2/24 Switch B Loopback 0 4.4.4.4/32 Switch C VLAN-interface 100 12.12.12.2/24 Switch C VLAN-interface 101 24.24.24.2/24

Configuration procedure

1. Configure IP addresses and subnet masks for interfaces on the switches. (Details not shown.)

2. Configure RIPv2 on the switches to make sure Switch A, Switch B, and Switch C can

communicate with each other at Layer 3. (Details not shown.)

3. Configure RIP FRR: # Configure Switch A.

<SwitchA> system-view [SwitchA] ip prefix-list abc index 10 permit 4.4.4.4 32 [SwitchA] route-policy frr permit node 10 [SwitchA-route-policy-frr-10] if-match ip address prefix-list abc [SwitchA-route-policy-frr-10] apply fast-reroute backup-interface vlan-interface

100 backup-nexthop 12.12.12.2 [SwitchA-route-policy-frr-10] quit [SwitchA] rip 1 [SwitchA-rip-1] fast-reroute route-policy frr [SwitchA-rip-1] quit

# Configure Switch B.

<SwitchB> system-view [SwitchB] ip prefix-list abc index 10 permit 1.1.1.1 32 [SwitchB] route-policy frr permit node 10 [SwitchB-route-policy-frr-10] if-match ip address prefix-list abc [SwitchB-route-policy-frr-10] apply fast-reroute backup-interface vlan-interface

101 backup-nexthop 24.24.24.2 [SwitchB-route-policy-frr-10] quit [SwitchB] rip 1 [SwitchB-rip-1] fast-reroute route-policy frr [SwitchB-rip-1] quit

Verifying the configuration

# Display route 4.4.4.4/32 on Switch A to view the backup next hop information.

[SwitchA] display ip routing-table 4.4.4.4 verbose

Summary Coun t : 1

Destination: 4.4.4.4/32 Protocol: RIP Process ID: 1

SubProtID: 0x 1 Age: 04h20m37s Cost: 1 Preference: 100 IpPre: N/ A QosLocalID: N/A Tag: 0 State: Active Adv OrigTblID: 0x0 OrigVrf: default-vrf TableID: 0x2 OrigAs: 0 NibID: 0x26000002 LastAs: 0 AttrID: 0xffffffff Neighbor: 13 .13.13.2 Flags: 0x1008c OrigNextHop: 13. 13.13.2 Label: NULL RealNex tHop: 13.13.13.2 BkLabel: NULL BkNextHop: 12.1 2.12.2 Tunnel ID: Inva lid Interface: Vlan-interface200 BkTunnel ID: Inva lid BkInterface: Vlan-interface100 FtnIndex: 0x0 TrafficIndex: N/A Connector: N/A

# Display route 1.1.1.1/32 on Switch B to view the backup next hop information.

[SwitchB] display ip routing-table 1.1.1.1 verbose

Summary Coun t : 1

Destination: 1.1.1.1/32 Protocol: RIP Process ID: 1 SubProtID: 0x1 Age: 04h20m37s Cost: 1 Preference: 100 IpPre: N/A QosLocalID: N/A Tag: 0 State: Active Adv OrigTblID: 0x0 OrigVrf: default-vrf TableID: 0x2 OrigAs: 0 NibID: 0x26000002 LastAs: 0 AttrID: 0xffffffff Neighbor: 13.13.1 3.1 Flags: 0x1008c OrigNextHop: 13.13.13.1 Label: NULL RealNex tHop: 13.13.13.1 BkLabel: NULL BkNextHop: 24.2 4.24.2 Tunnel ID: Inva lid Interface: Vlan-interface200 BkTunnel ID: Inva lid BkInterface: Vlan-interface101 FtnIndex: 0x0 TrafficIndex: N/A Connector: N/A

•

Configuring OSPF

Overview

Open Shortest Path F irst (OSPF) is a link-state IGP developed by the OSPF work ing group of the IETF. OSPF version 2 is used for IPv4. OSPF refers to OSPFv2 throughout this chapter.

OSPF has the following features:

Wide scope—Supports multiple network sizes and several hundred routers in an OSPF routing

domain.

Fast convergence—Advertises routing updates instantly upon network topology changes. Loop free—Computes routes with the SPF algorithm to avoid routing loops. Area-based network partition—Splits an AS into multiple areas to facilitate management.

This feature reduces the LSDB size on routers to save memory and CPU resources, and reduces route updates transmitted between areas to save bandwidth.

ECMP routing—Supports multiple equal-cost routes to a destination. Routing hierarchy—Supports a 4-level routing hierarchy that prioritizes routes into intra-area,

inter-area, external Type-1, and external Type-2 routes.

Authentication—Supports area- and interface-based packet authentication to ensure secure

packet exchange.

Support for multicasting—Multicasts protocol packets on some types of links to avoid

impacting other devices.

OSPF packets

OSPF messages are carried directly over IP. The protocol number is 89. OSPF uses the following packet types:

Hello—Periodically sent to find and maintain neighbors, containing timer values, information

about the DR, BDR, and known neighbors.

Database description (DD)—Describes the digest of each LSA in the LSDB, exchanged

between two routers for data synchronization.

Link state request (LSR)—Requests needed LSAs from a neighbor. After exchanging the DD

packets, the two routers know which LSAs of the neighbor are missing from their LSDBs. They then exchange LSR packets requesting the missing LSAs. LSR packets contain the digest of the missing LSAs.

Link state update (LSU)—Transmits the requested LSAs to the neighbor. Link state acknowledgment (LSAck)—Acknowledges received LSU packets. It contains the

headers of received LSAs (an LSAck packet can acknowledge multiple LSAs).

LSA types

OSPF advertises routing inform ation in Link State Advertisem ents (LSAs). The f ollowing LSAs are commonly used:

Router LSA—Type-1 LSA, originat ed b y all routers and flooded throughout a single area only.

This LSA describes the collected states of the router's interfaces to an area.

•

Area 0

Area 1

Area 2

Area 3

Area 4

Network LSA—Type-2 LSA, originated for broadcast and NBMA networks by the designated

router, and flooded throughout a single area only. This LSA contains the list of routers connected to the network.

Network Summary LSA—Type-3 LSA, originated by Area Border Routers (ABRs), and

flooded throughout the LSA's associated area. Each summary-LSA describes a route to a destination outside the area, yet still inside the AS (an inter-area route).

ASBR Summary LSA—Type-4 LSA, originated by ABRs and flooded throughout the LSA's

associated area. Type 4 summary-LSAs describe routes to Autonomous System Boundary Router (ASBR).

AS External LSA—Type-5 LSA, originated by ASBRs, and flooded throughout the AS (except

stub and NSSA areas). Each AS-external-LSA describes a route to another AS.

NSSA LSA—Type-7 LSA, as defined in RFC 1587, originated by ASBRs in NSSAs and flooded

throughout a single NSSA. NSSA LSAs describe routes to other ASs.

Opaque LSA—A proposed type of LSA. Its format consists of a standard LSA header and

application specific information. Opaque LSAs are used by the OSPF protocol or by some applications to distribute information into the OSPF routing domain. The opaque LSA includes Type 9, T ype 10, and Type 1 1. The Ty pe 9 opaque LSA is flooded into the local subnet, the Type 10 is flooded into the local area, and the Type 11 is flooded throughout the AS.

OSPF areas

In large OSPF routing domains, SPF route computations consume too many storage and CPU resources, and enormous OSPF packets generated for route synchronization occupy excessive bandwidth.

To resolve these issues, OSPF splits an AS into multiple areas. Each area is identified by an area ID. The boundaries between areas are routers rather than links. A network segment (or a link) can only reside in one area as shown in Figure 17.

You can configure route su m m arizati on on ABRs to reduce the num ber of LSAs a dvert ised to other areas and minimize the effect of topology changes.

Figure 17 Area-based OSPF network partition

•

Area 0

Area 1

Area 2

ABRABR

Transit area

Virtual link

Area 0

Area

Virtual link

Backbone area and virtual links

Each AS has a bac kbone area that distrib utes routing information between non-back bone areas. Routing information between non-backbone areas must be forwarded by the backbone area. OSPF has the following requirements:

All non-backbone areas must maintain connectivity to the backbone area. The backbone area must maintain connectivity within itself.

In practice, these requirements might not be met due to lack of physical links. OSPF virtual links can solve this issue.

A virtual link is established bet we en t wo AB Rs thr oug h a non-backbone area. It mus t be c onf igure d on both ABRs to take effect. The non-backbone area is called a transit area.

As shown in Figure 18, Area 2 has no direct physical link to the backbone Area 0. Y ou can configure a virtual link between the two ABRs to connect Area 2 to the backbone area.

Figure 18 Virtual link application 1

Virtual links can also be used as redundant links. If a physical link failure breaks the internal connectivity of the backbone area, you can configure a virtual link to replace the failed physical link, as shown in Figure 19.

Figure 19 Virtual link application 2

The virtual link between the two ABRs acts as a point-to-point connection. You can configure interface param eters, such as hello inter val, on the virtual link as they are c onfig ured on a ph ysical interface.

The two ABRs on the virtual link unicast OSPF packets to each other, and the OSPF routers in between convey these OSPF packets as normal IP packets.

Stub area and totally stub area

A stub area does not distribute Type-5 LSAs to r educe the r outing tab le size and LS As advertised within the area. T he ABR of the stub ar ea advertises a default route in a Type-3 LSA so that the routers in the area can reach external networks through the default route.

To further reduce the routin g tabl e size and advert ised LSAs, you can c onf igure t he stub area as a totally stub area. T he ABR of a totally stub are a does not advertise inter -area routes or external

•

NSSA

Area

Type 7

Type 5

Type

Type 5

Area 0

Area 1

NSSA ABR

ABR

NSSA ASBR

ASBR

RIP

routes. It advertises a default route in a Type-3 LSA so that the routers in the area can reach external networks through the default route.

NSSA area and totally NSSA area

An NSSA area does not import AS external LSAs (Type-5 LSAs) but can import Type-7 LSAs generated by the NSSA ASBR. The NSSA ABR translates Type-7 LSAs into Type-5 LSAs and advertises the Type-5 LSAs to other areas.

As shown in Figure 20, the OSPF AS contains Area 1, Area 2, and Area 0. The other two ASs run RIP . Area 1 is an NSSA area where the ASBR redistributes RIP routes in Type-7 LSAs into Area 1. Upon receiving the Type-7 LSAs, the NSSA ABR translates them to Type-5 LSAs, and advertises the Type-5 LSAs to Area 0.

The ASBR of Area 2 redistributes RIP routes in Type-5 LSAs into the OSPF routing domain. However, Area 1 does not receive Type-5 LSAs because it is an NSSA area.

Figure 20 NSSA area

Router types

OSPF routers are classified into the following types based on their positions in the AS:

Internal router—All interfaces on an internal router belong to one OSPF area. ABR—Belongs to more than two areas, one of which must be the backbone area. ABR

connects the backbone area to a non-backbone area. An ABR a nd the backbone area can be connected through a physical or logical link.

Backbone router—No less than one interface of a backbone router must reside in the

backbone area. All ABRs and internal routers in Area 0 are backbone routers.

ASBR—Exchanges routing information with another AS is an ASBR. An ASBR might not res ide

on the border of the AS. It can be an internal router or an ABR.

•

Area 1

Area 2

Area 3

Area 4

Backbone router

ASBR

IS-IS

RIP

Internal router

ABR

Area 0

Figure 21 OSPF router types

Route types

OSPF prioritizes routes into the following route levels:

Intra-area route. Inter-area route. Type-1 external route. Type-2 external route.

The intra-area and inter -area routes des cribe the network topology of the AS . The external routes describe routes to external ASs.

A Type-1 ex ternal r oute ha s high cred ibil ity. The cost of a Type-1 external route = the cost f rom the router to the corresponding ASBR + the cost from the ASBR to the destination of the external route.

A Type-2 ex ternal route has low credibility. OSPF considers that t he cost from the ASBR to the destination of a Type-2 external route is much greate r than the cost from the A SBR to an OSPF internal router. The cost of a Type-2 external route = the cost from the ASBR to the destination of the Type-2 external route. If two Type-2 routes to the same destination have the same cost, OSPF takes the cost from the router to the ASBR into consideration to determine the best route.

Route calculation

OSPF computes routes in an area as follows:

Each router generates LSAs based on the network topology around itself, and sends them to

other routers in update packets.

Each OSPF router collects LSAs from other routers to compose an LSDB. An LSA describes

the network topology around a router, and the LSDB describes the entire network topology of the area.

•

Each router transforms the LSDB to a weighted directed graph that shows the topolog y of the

area. All the routers within the area have the same graph.

Each router uses the SPF algorithm to compute a shortest path tree that shows the routes to the

nodes in the area. The router itself is the root of the tree.

OSPF network types

OSPF classifies networks into the following types, depending on different link layer protocols:

Broadcast—If the link layer protocol is Ethernet or FDDI, OSPF considers the network type as

broadcast by default. On a broadcast network, hello, LSU, and LSAck packets are multicast to

224.0.0.5 that identifies all OSPF routers or to 224.0.0.6 that identifies the DR and BDR. DD packets and LSR packets are unicast.

NBMA—If the link layer protocol is Frame Relay, ATM, or X.25, OSPF considers the network

type as NBMA by default. OSPF packets are unicast on an NBMA network.

P2MP—No link is P2MP type by default. P2MP must be a conversion from other network types

such as NBMA. On a P2MP network, OSPF packets are multicast to 224.0.0.5.

P2P—If the link layer protocol is PPP or HDLC, OSPF considers the network type as P2P . On a

P2P network, OSPF packets are multicast to 224.0.0.5.

The following are the differences between NBMA and P2MP networks:

NBMA networks are fully meshed. P2MP networks are not required to be fully meshed. NBMA networks require DR and BDR election. P2MP networks do not have DR or BDR. On an NBMA network, OSPF packets are unicast, and neighbors are manually configured. On a

P2MP network, OSPF packets are multicast by default, and you can configure OSPF to unicast protocol packets.

DR and BDR

DR and BDR mechanism

On a broadcast or NBMA network, any two routers must establish an adjacency to exchange routing information with each other. If n routers are present on the network, n(n-1)/2 adjacencies are established. Any topology change on the network results in an increase in traffic for route synchronization, which consumes a large amount of system and bandwidth resources.

Using the DR and BDR mechanisms can solve this problem.

DR—Elected to advertise routing information among other routers. If the DR fails, routers on the

network must elect another DR and synchronize information with the new DR. Using this mechanism without BDR is time-consuming and is prone to route calculation errors.

BDR—Elected along with the DR to establish adjacencies with all other routers. If the DR fails,

the BDR immediately becomes the new DR, and other routers elect a new BDR.

Routers other than the DR and BDR are cal led DR Others. They do not establish adj acencies wit h one another, so the number of adjacencies is reduced.

The role of a router is subnet (or interface) specific. It might be a DR on one interface and a BDR or DR Other on another interface.

As shown in Figure 22, solid lines are Ethernet physical links , and dashed lines represent OSPF adjacencies. With the DR and BDR, only seven adjacencies are established.

NOTE:

are different concepts. After startup, OSPF sends a hello packet on each OSPF interface. A receiving router checks parameters in the packet. If the parameters match its own, the receiving router considers the sending router an OSPF n neighbors establish an adjacency

e their LSDBs through exchange

of DD packets and LSAs.

•

DR BDR

DR other DR otherDR other

Physical links Adjacencies

Figure 22 DR and BDR in a network

n OSPF, neighbor and adjacency

eighbor. Two OSPF

relationship after they synchroniz

DR and BDR election

DR election is performed on broadcast or NBMA networks but not on P2P and P2MP networks. Routers i n a broadcast or NBMA network elect the DR and BDR by router pri ority and ID. Routers

with a router priority value higher than 0 are candidates for DR and BDR election. The election votes are hello packets. Each router sends the DR elected by itself in a hello packet to

all the other routers. If two routers on the network declare themselves as the DR, the router with the higher router priority wins. If router priorities are the same, the router with the higher router ID wins.

If a router with a higher router priority becomes active after DR and BDR election, the router cannot replace the DR or BDR until a new elect ion is performed. Therefore, t h e DR of a network might not be the router with the highe st prior ity, and the BDR might not b e the rou ter with the s econd high est priority.

Protocols and standards

RFC 1765, OSPF Database Overflow RFC 2328, OSPF Version 2 RFC 3101, OSPF Not-So-Stubby Area (NSSA) Option RFC 3137, OSPF Stub Router Advertisement RFC 4811, OSPF Out-of-Band LSDB Resynchronization RFC 4812, OSPF Restart Signaling RFC 4813, OSPF Link-Local Signaling

OSPF configuration task list

To run OSPF, you must first enable OSPF on t he rout er. Make a prop er conf igur ation plan to a void incorrect settings that can result in route blocking and routing loops.

To configure OSPF, perform the following tasks:

Tasks at a glance

(Required.) Enabling OSPF (Optional.) Configuring OSPF areas:

• Configuring a stub area

• Configuring an NSSA area

• Configuring a virtual link

(Optional.) Configuring OSPF network types:

• Configuring the broadcast network type for an interface

• Configuring the NBMA network type for an interface

• Configuring the P2MP network type for an interface

• Configuring the P2P network type for an interface

(Optional.) Configuring OSPF rout e contr ol:

• Configuring OSPF route summarization

 Configuring route summarization on an ABR  Configuring route summarization on an ASBR

• Configuring received OSPF route filtering

• Configuring Type-3 LSA filtering

• Setting an OSPF cost for an interface

• Setting the maximum number of ECMP routes

• Setting OSPF preference

• Configuring discard routes for summary networks

• Configuring OSPF route redistribution

 Redistributing routes from another routing protocol  Redistributing a default route  Configuring default parameters for redistributed routes

• Advertising a host route

• Excluding interfaces in an OSPF area from the base topology

Tasks at a glance

(Optional.) Tuning and optimizing OSPF networks:

• Setting OSPF timers

• Setting LSA trans mi ss ion del a y

• Setting SPF calculation interval

• Setting the LSA arrival interval

• Setting the LSA generation interval

• Disabling interfaces from receiving and sending OSPF packets

• Configuring stub routers

• Configuring OSPF authentication

• Adding the interface MTU into DD packets

• Setting the DSCP value for outgoing OSPF packets

• Setting the maximum number of external LSAs in LSDB

• Setting OSPF exit overflow interval

• Enabling compatibility with RFC 1583

• Logging neighbor state changes

• Configuring OSPF network management

• Setting the LSU transmit rate

• Setting the maximum length of OSPF packets that can be sent by an interface

• Enabling OSPF ISPF

• Configuring prefix suppression

• Configuring prefix prioritization

• Configuring OSPF PIC

• Setting the number of OSPF logs

• Filtering outbound LSAs on an interface

• Filtering LSAs for the specified neighbor

• Configuring GTSM for OSPF

(Optional.) Configuring OSPF G R

• Configuring OSPF GR restarter

• Configuring OSPF GR helper

• Triggering OSPF GR

(Optional.) Configuring OSPF N SR (Optional.) Configuring BFD for OSPF (Optional.) Configuring OSPF F RR (Optional.) Advertising OSPF link state information to BGP

Enabling OSPF

Enable OSPF before you perform other OSPF configuration tasks.

Configuration p rerequisites

Configure the link layer pro tocol and I P addresses for interf aces to ens ure I P connec tivit y bet ween neighboring nodes.

•

Step

Command

Remarks

Configure a

, no global router ID is

if any, is used as the router ID. If no

address is

s is used,

Enable an OSPF process

(Optional.) Configure a description for the OSPF

(Optional.) Configure a

Specify a network to enable the interface attached to the network to run the OSPF process in

Configuration guidelines

To enable OSPF on an interface, you ca n ena ble O SP F on the network where the interf ac e res ides or directly enable OSPF on that interface. If you configure both, the latter takes precedence.

You can specify a global router ID, or specify a router ID when you create an OSPF process.

If you specify a router ID when you create an OSPF process , any two routers in an AS must

have different router IDs. A common practice is to specify the IP address of an interface as the router ID.

If you specify no router ID when you create the OSPF process, the global router ID is used. As

a best practice, specify a router ID when you create the OSPF process.

OSPF supports multiple processes and VPNs.

To run multiple OSPF processes, you must specify an ID for each process. The process IDs

take effect locally and has no influence on packet exchange between routers. Two routers with different process IDs can exchange packets.

You can configure an OSPF process to run in a specified VPN instance. For more information

about VPN, see MPLS Configuration Guide.

Enabling OSPF on a network

1. Enter system view.

2. (Optional.)

global router ID.

and enter OSPF view.

process.

5. Create an OSPF area and enter OSPF area view.

description for the area.

the area.

system-view

router id

ospf [

router-id | vpn-instance-name ] *

description

area

description

network

wildcard-mask

router-id

process-id |

area-id

vpn-instance

text

router-id

ip-address

N/A By default

configured. If no global router ID is configured, the

highest loopback interf ac e IP address, loopback interface IP

available, the highest physical interface IP addres regardless of the interface status (up or down).

By default, OSPF is disabled.

By default, no description is configur ed for the OSPF process.

As a best practice, configure a description for each OSPF process.

By default, no OSPF areas exist. By default, no description is configur ed

for the area. As a best practice, configure a

description for each OSPF area.

By default, no network is specified. A network can be added to only one

area.

Step

Command

Remarks

nable an OSPF process

y default, OSPF is disabled on an

not exist, the command creates the OSPF

Disabling an OSPF

•

Step

Command

Remarks

Configure the area as a

(Optional.) Set a cost for

Enabling OSPF on an interface

1. Enter system view.

2. Enter interface view.

3. E

on the interface.

system-view interface

interface-number

ospf

area-id [

interface-type

process-id

exclude-subip ]

Configuring OSPF areas

Before you configure an OSPF area, perform the following tasks:

Configure IP addresses for interfaces to ensure IP connectivity between neigh bori ng nodes . Enable OSPF.

Configuring a stub area

You can configure a non-bac kbone ar ea at an AS edg e as a stub ar ea. To do so, execute the stub command on all routers attached to the area. The routing table size is reduced because Type-5 LSAs will not be flooded w ith in the stub area. The ABR gen e r ates a default route into th e stub area so all packets destined outside of the AS are sent through the default route.

area

N/A

B interface.

If the specified OSPF process and area do process and area.

process on an interf ace does not delet e the OSPF process or the area.

T o further reduce the routing table size and routing information exchanged in the stub area, configure a totally stub area b y using the stub no-summary c ommand on th e ABR. AS ex ternal routes and inter-area routes will not be distri buted into the area. All the pac kets destine d outside of the AS or area will be sent to the ABR for forwarding.

A stub or totally stub area cannot have an ASBR because external routes cannot be distributed into the area.

To configure an OSPF stub area:

1. Enter system view.

2. Enter OSPF view.

3. Enter area view.

stub area.

the default route advertised to the stub area.

system-view ospf [

router-id | vpn-instance-name ] *

area stub

[

default-cost

process-id |

area-id

default-route-advertise-alwa

no-summary

cost-value

router-id

vpn-instance

] *

N/A

By default, no stub area is configured.

The default setting is 1.

default-cost

The takes effect only on the ABR of a stub area or totally stub area.

cost command

Step

Command

Remarks

Configure the area as an

] |

a cost for

the ABR/ASBR of an NSSA or

Step

Command

Remarks

onfigure this command on both

Configuring an NSSA area

A stub area can not import external routes , but an NSSA area can import external routes into the OSPF routing domain while retaining other stub area characteristics.

Do not configure the backbone area as an NSSA area or totally NSSA area. To configure an NSSA area, configure the nssa command on all the routers attached to the area. To configure a totally NSSA area, configur e the nssa com mand on all the ro uters attached to t he

area and configure t he nssa no-summary c om mand on the ABR. The A BR of a totally NSS A area does not advertise inter-area routes into the area.

To configure an NSSA area:

1. Enter system view.

2. Enter OSPF view.

3. Enter area view.

NSSA area.

5. (Optional.) Set the default route advertised to the NSSA area.

Configuring a virtual link

Virtual links are configured for connecting backbone area routers that have no dire c t phys ical links.

system-view ospf [

router-id | vpn-instance-name ] *

area nssa [ default-route-advertise

[

route-policy type no-summary

[ [ [

translate-ignore-checking-bac

[

kbone translator-stability-interval

value ] *

default-cost

area-id

cost

type ] * |

process-id |

cost-value |

route-policy-name |

no-import-route

translate-always

translate-never

] ] |

cost-value

router-id

vpn-instance

nssa-only

suppress-fa

]

N/A

By default, no area is configured as an NSSA area.

The default setting is 1. This co mmand takes e ffect o nly on

totally NSSA area.

To configure a virtual link:

1. Enter system view.

2. Enter OSPF view.

3. Enter area view.

4. Configure a virtual link.

system-view ospf [

router-id | vpn-instance-name ] *

area vlink-peer

seconds | { {

cipher | plain

{ keychain-name | |

seconds |

process-id |

area-id

hmac-md5

plain

} string } |

vpn-instance

router-id [

hello

seconds |

md5

} string |

simple

trans-delay

router-id

dead

} key-id

keychain

cipher

{

retransmit

seconds ] *

N/A

By default, no virtual links exist. C

ends of a virtual link. The

dead

intervals must be identical on

both ends of the virtual link.

hello

and

•

Step

Command

Remarks

type for the interface as

y default, the network type of an

interface depends on the link layer

(Optional.) Set a router

Configuring OSPF network types

OSPF classifies networks into the following types based on the link layer protocol:

Broadcast—When the link layer protocol is Ethernet or FDDI, OSPF classifies the network type

as broadcast by default.

NBMA—When the link layer protocol is Frame Relay, ATM, or X.25, OSPF classifies the

network type as NBMA by default.

P2P—When the link layer protocol is PPP, LAPB, or HDLC, OSPF classifies the network type

as P2P b y defau lt.

When you change the network type of an interface, follow these guidelines:

When an NBMA network becomes fully meshed, change the network type to broadcast to avoid

manual configuration of neighbors.

If any routers in a broadcast network do not support multicasting, change the network type to

NBMA.

An NBMA network must be fully meshed. OSPF requires that an NBMA network be fully

meshed. If a network is partially meshed, change the network type to P2MP.

If a router on an NBMA network has only one neighbor, you can change the network type to P2P

to save costs.

Two broadcast-, NBMA-, and P2MP-interfaces can establish a neighbor relationship only when they are on the same network segment.

Configuration p rerequisites

Before you configure OSPF network types, perform the following tasks:

Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes. Enable OSPF.

Configuring the broadcast network type for an interface

1. Enter system view.

2. Enter interface view.

3. Configure the OSPF network

broadcast.

priority for the interface.

system-view interface

interface-number

ospf network-type broadcast

ospf dr-priority

interface-type

priority

N/A

B protocol.

The default router priority is 1.

Configuring the NB M A network type for an interface

After you configure the network type as NBMA, you must specify neighbors and their router priorities because NBMA interfaces cannot find neighbors by broadcasting hello packets .

To configure the NBMA network type for an interface:

Step

Command

Remarks

Configure the OSPF network type for the

By default, the network type of an

link layer

(Optional.) Set a router

Specify a neighbor and

whether a

neighbor as 0, the local router

etermines the neighbor has no

the local router is the DR or BDR, it still sends hello packets to the neighbor for neighbor relationship

Step

Command

Remarks

Configure the OSPF network type for the

By default, the network type of an

After you configure the OSPF network type for an interface as P2MP unicast, all packets are unicast over the interface. The interface cannot broadcast hello

r neighbors, so

you must manually specify the

1. Enter system view.

2. Enter interface view.

interface as NBMA.

priority for the interface.

5. Return to system view.

6. Enter OSPF view.

set its router priority.

system-view interface

interface-number

ospf network-type nbma

ospf dr-priority

quit ospf [

router-id | vpn-instance-name ] *

peer

priority ]

interface-type

priority

process-id |

vpn-instance

ip-address [

dr-priority

router-id

N/A

interface depends on the protocol.

The default setting is 1. The router priority configured with this

command is for DR election. N/A

N/A

By default, no neighbor is specified. The priority configured with this

command indicates neighbor has the election right or not. If you configure the ro uter pr iority for a

d election right, and does not send hello packets to this neighbor. However, if

Configuring the P2MP network type for an interface

1. Enter system view.

2. Enter interface view.

interface as P2MP.

4. Return to system view.

5. Enter OSPF view.

system-view interface

interface-number

ospf network-type p2mp

unicast

[

quit ospf [

router-id | vpn-instance-name ] *

interface-type

]

process-id |

router-id

vpn-instance

establishment.

N/A

interface depends on the link layer protocol.

packets to discove neighbors.

N/A

Step

Command

Remarks

(Optional.) Specify a neighbor and set its router

is optional if the network type is

Step

Command

Remarks

Configure the OSPF network type for the

By default, the network type of an

•

Step

Command

Remarks

system-view

By default, no neighbor is specified.

priority.

peer

ip-address [

cost-value ]

This step must be performed if the

cost

network type is P2MP unicast, and P2MP.

Configuring the P2P network type for an interface

1. Enter system view.

2. Enter interface view.

interface as P2P.

system-view interface

interface-number

ospf network-type p2p

peer-address-check ]

[

interface-type

Configuring OSPF route control

This section describes how to control the advertisement and reception of OSPF routing information, as well as route redistribution from other protocols.

Configuration p rerequisites

Before you configure OSPF route control, perform the following tasks:

Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes. Enable OSPF. Configure filters if routing information filtering is needed.

Configuring OSPF route summarization

N/A

interface depends on the link layer protocol.

Route summarization enables an ABR or ASBR to su mmarize contiguous networks into a single network and advertise the network to other areas.

Route summarizatio n reduces the routing inform ation exchanged b etween areas and the size of routing tables, and improves routing performance. For example, three internal networks 19.1.1.0/24,

19.1.2.0/24, and 19.1.3.0/ 24 are available within an area. You can summarize the thr ee networks into network 19.1.0.0/16, and advertise the summary network to other areas.

Configuring route summarization on an ABR

After you configure a s ummary route on an ABR, t he ABR generates a summary LSA instead of specific LSAs. The sc ale of LSDBs on r o uter s in ot her areas and th e inf lu enc e of topo logy changes are reduced.

To configure route summarization on an ABR:

1. Enter system view.

N/A

Step

Command

Remarks

Configure ABR route

•

Step

Command

Remarks

system-view

Configure ASBR route

route summarization is

•

Step

Command

Remarks

2. Enter OSPF view.

3. Enter OSPF area view.

summarization.

ospf [

router-id | vpn-instance-name ] *

area abr-summary

{ mask-length | mask } [

not-advertise

process-id |

area-id

Configuring route summarization on an ASBR

Perform this task to enabl e an ASBR to summarize external ro utes within the specified address range into a single rou te. The ASBR advertises only the summ ary route to reduce the num ber of LSAs in the LSDB.

An ASBR can summarize routes in the following LSAs:

Type-5 LSAs. Type-7 LSAs in an NSSA area. Type-5 LSAs translated by the ASBR (also an ABR) from Type-7 LSAs in an NSSA area.

If the ASBR (ABR) is not a translator, it cannot summarize routes in Type-5 LSAs translated from Type-7 LS As .

To configure route summarization on an ASBR:

router-id

vpn-instance

ip-address

advertise

cost

] [

cost-value ]

N/A

By default, route summarization is

not configured on an ABR.

1. Enter system view.

2. Enter OSPF view.

summarization.

ospf [

process-id |

vpn-instance

| *

asbr-summary

{ mask-length | mask } [ cost-value |

nssa-only

router-id

vpn-instance-name ]

ip-address

not-advertise

tag

tag ] *

router-id

cost

Configuring received OSPF route filtering

Perform this task to filter routes calculated using received LSAs. The following filtering methods are available:

Use an ACL or IP prefix list to filter routing inf ormation by destination address . Use the gateway keyword to filter routing information by next hop. Use an ACL or IP prefix list to filter routing information by destination address. At the same time

use the gateway keyword to filter routing information by next hop.

Use a routing policy to filter routing information.

To configure OSPF to filter routes calculated using received LSAs:

N/A

By default, not configured on an ASBR.

1. Enter system view.

2. Enter OSPF view.

system-view ospf [

vpn-instance

process-id |

router-id

vpn-instance-name ] *

router-id |

N/A

Step

Command

Remarks

calculated using

import

Step

Command

Remarks

3 LSA

By default, the ABR does not

•

Step

Command

Remarks

Set an OSPF cost for

By default, the OSPF cost is calculated according to the interface bandwidth.

3. Configure OSPF to filter routes

received LSAs.

filter-policy

prefix-list-name ] |

prefix-list

prefix-list-name ] | route-policy-name }

{ ipv4-acl-number [

gateway

prefix-list-name [

Configuring Type-3 LSA filtering

Perform this task to filter Type-3 LSAs advertised to an area on an ABR. T o configure Type-3 LSA filtering:

1. Enter system view.

2. Enter OSPF view.

3. Enter area view.

4. Configure Type-

filtering.

system-view ospf [

process-id |

vpn-instance

| *

area

area-id

filter

{ ipv4-acl-number | prefix-list-name | route-policy-name } {

import

}

gateway

prefix-list-name

gateway

route-policy

router-id

vpn-instance-name ]

prefix-list

route-policy

export

router-id

By default, OSPF accepts all routes calculated using received LSAs.

N/A

filter Type-3 LSAs.

Setting an OSPF cost for an interface

Set an OSPF cost for an interface by using either of the following methods:

Set the cost value in interface view. Set a bandwidth reference value for the interface. OSPF computes the cost with this formula:

Interface OSPF cost = Bandwidth reference value (100 Mbps) / Expected interface bandwidth (Mbps). The expected bandwidth of an interface is configured with the bandwidth command (see Interface Command Reference).

 If the calculated cost is greater than 65535, the value of 65535 is used. If the calculated cost

is less than 1, the value of 1 is used.

 If no cost or bandwidth reference value is configured for an interface, OSPF computes the

interface cost based on the interface bandwidth and default bandwidth reference value.

To set an OSPF cost for an interface:

1. Enter system view.

2. Enter interface view.

the interface.

To set a bandwidth reference value:

system-view interface

interface-number

ospf cost

interface-type

cost-value

N/A

For a loopback interface, the O SPF cost is 0 by default.

Step

Command

Remarks

Step

Command

Remarks

By default, the maximum number of ECMP routes equals the maximum number

Step

Command

Remarks

Set a preference for

of OSPF

Step

Command

Remarks

1. Enter system view.

2. Enter OSPF view.

3. Set a bandwidth

reference value.

system-view ospf [

router-id | vpn-instance-name ] *

bandwidth-reference

process-id |

vpn-instance

router-id

value

N/A

The default setting is 100 Mbps.

Setting the maxim um number of ECMP routes

Perform this task to implement load sharing over ECMP routes. To set the maximum number of ECMP routes:

1. Enter system view.

2. Enter OSPF view.

3. Set the maximum number of

ECMP routes.

system-view ospf [

process-id |

vpn-instance

| *

maximum load-balancing

router-id

vpn-instance-name ]

N/A

router-id

N/A

number

of ECMP routes supported by the system.

Setting OSPF preference

A router can ru n multiple ro uting protoco ls, and each protocol is assigned a prefer ence. If mu ltiple routes are available to the same destination, the one with the highest protocol preference is selected as the best route.

To set OSPF preference:

1. Enter system view.

2. Enter OSPF view.

OSPF.

system-view ospf [

process-id |

vpn-instance

preference route-policy

[

router-id

vpn-instance-name ] * N/A

ase

] { preference |

route-policy-name } *

router-id

N/A

By default, the preference internal routes is 10 and the preference of OSPF external routes is 150.

Configuring discard routes for summary networks

Perform this task on an A BR or ASBR to spec ify whether to gener ate discard routes for summar y networks. You can also specify a preference for the discard routes.

1. Enter system view.

system-view

N/A

Step

Command

Remarks

Configure discard routes

} |

discard routes for summary

he preference of discard

IMPORTANT:

The

allow

it with caution.

Step

Command

Remarks

Configure OSPF to redistribute routes from

o route

) Configure

OSPF to filter

Step

Command

Remarks

2. Enter OSPF view.

for summary networks.

ospf [

router-id | vpn-instance-name ] *

discard-route

{ preference |

internal suppression

process-id |

{

suppression

{ preference |

} } *

router-id

vpn-instance

external

Configuring OSPF route redistribution

On a router running OSPF and other routing protocols, you can configure OSPF to redistribute static routes, direct routes, or r ou tes f rom other prot ocols , s u ch as RIP, IS-IS, and BGP. OSPF advertises the routes in Type-5 LSAs or Ty pe-7 LSAs. In addition, you can configure OSPF to filter redistributed routes so that OSPF advertises only permitted routes.

import-route bgp command redistributes only EBGP routes. Because the import-route bgp

-ibgp co mmand redistributes both EBGP and IBGP routes, and might cause routing loops, use

Redistributing routes from another routing protocol

N/A

By default:

• The ABR or ASBR generates networks.

• T routes is 255.

1. Enter system view.

2. Enter OSPF view.

another routing protocol.

4. (Optional. redistributed routes.

Redistributing a default route

The import-route command cannot redistribute a default external route. Perform this task to redistribute a default route.

To redistribute a default route:

1. Enter system view.

2. Enter OSPF view.

system-view ospf [

process-id |

vpn-instance

import-route

[ process-id |

allow-ibgp

cost-value | route-policy-name |

filter-policy prefix-list

[ protocol [ process-id ] ]

system-view ospf [

vpn-instance

] [

prefix-list-name }

process-id |

router-id

vpn-instance-name ] *

protocol [ as-number ]

all-processes

allow-direct

nssa-only

tag

{ ipv4-acl-number |

router-id

vpn-instance-name ] *

router-id |

route-policy

type

tag |

export

router-id |

cost

type ]

N/A

By default, n redistribution is configured.

This command redistributes only active routes. To view information about active routes, use the

protocol

By default, OSPF accepts all redistributed routes.

display ip routing-table

command.

N/A

Step

Command

Remarks

Redistribute a default

This command is applicable only to VPNs. The PE router

Step

Command

Remarks

Configure the default parameters for redistributed routes

Step

Command

Remarks

o host route is

Step

Command

Remarks

Exclude interfaces in the OSPF area from the base

default-route-advertise permit-calculate-other

route.

cost-value | route-policy-name |

default-route-advertise cost

cost-value ]

[ [

] |

route-policy

type

type ] * [

Configuring default parameters for redistributed routes

Perform this task to configure default param eters for redistribute d routes, including cos t, tag, and type. T ags identify information about protocols. For example, when redistributing BGP routes, OSPF uses tags to identify AS IDs.

To configure the default parameters for redistributed routes:

1. Enter system view.

2. Enter OSPF view.

(cost, upper limit, tag, and type).

system-view ospf [

vpn-instance

default { cost

type } *

process-id |

router-id

vpn-instance-name ] *

cost-value |

always

summary

router-id |

tag

tag |

By default, no default route is

cost

redistributed.

advertises a default route in a Type-3 LSA to a CE router.

N/A

type

By default, t he cost is 1, the tag is 1, and the type is Type-2.

Advertising a host r oute

1. Enter system view.

2. Enter OSPF view.

3. Enter area view.

4. Advertise a host route.

system-view ospf [

router-id | vpn-instance-name ] *

area

host-advertise

process-id |

vpn-instance

area-id

ip-address cost

router-id

N/A

N/A By default, n

advertised.

Excluding interfaces in an OSPF area from the base topology

1. Enter system view.

2. Enter OSPF view.

3. Enter area view.

topology.

system-view ospf [

router-id | vpn-instance-name ] *

area

area-id

capability default-exclusion

process-id |

vpn-instance

router-id

N/A

N/A By default, interfaces in an O SPF

area belong to the base topolo gy.

•

Step

Command

Remarks

The hello interval on P2P and broadcast interfaces is 10

The hello interval on P2MP and

The poll interval is a minimum of four

Tuning and optimizing OSPF networks

You can use one of the following methods to optimize an OSPF network:

Change OSPF packet timers to adjust the convergence speed and network load. On low-speed

links, consider the delay time for sending LSAs.

Change the SPF calculation interval to reduce resource consumption caused by frequent

network changes.

Configure OSPF authentication to improve security.

Configuration p rerequisites

Before you configure OSPF network optimization, perform the following tasks:

Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes. Enable OSPF.

Setting OSPF timers

An OSPF interface includes the following timers:

Hello timer—Interval for sending hello packets. It must be identical on OSPF neighbors. Poll timer—Interval for sending hello packets to a neighbor that is down on the NBMA network. Dead timer—Interval within which if the interface does not receive any hello packet from the

neighbor, it declares the neighbor is down.

LSA retransmission timer—Inter va l with in whic h if th e interf ac e does not receive any

acknowledgment packets after sending an LSA to the neighbor, it retransmits the LSA.

To set OSPF timers:

1. Enter system view.

2. Enter interface view.

3. Set the hello interval.

4. Set the poll interval.

system-view interface

interface-number

ospf timer hello

ospf timer poll

interface-type

seconds

N/A

By default:

• seconds.

• NBMA interfaces is 30 seconds.

The default hello interval is restored when the n etwork type f or an in terface is changed.

The default setting is 120 seconds.

times the hello interval.

Step

Command

Remarks

The dead interval on P2P and broadcast interfaces is 40

The dead interval on P2MP and

four times the hello interval on an

A retransmission interval setting that is

Step

Command

Remarks

the LSA transmission

Step

Command

Remarks

By default:

• seconds.

•

5. Set the dead interval.

ospf timer dead

seconds

NBMA interfaces is 120 seconds.

The dead interval must be a minimu m of interface.

The default dead interval is restored when the n etwork type f or an in terface is changed.

The default setting is 5 seconds.

6. Set the retransmission interval.

ospf timer retransmit

Setting LSA transmission delay

To avoid LSAs from aging out during tr ansmission, set an L SA retransmission delay especial ly for low speed links.

To set the LSA transmission delay on an interface:

1. Enter system view.

2. Enter interface view.

3. Set

delay.

system-view interface

interface-number

ospf trans-delay

interface-type

Setting SPF ca lculation interv al

interval

seconds

too small can cause unnecessary LSA retransmissions. This interval i s typically set bigger than the round-trip time of a packet between two neighbors.

N/A

The default setting is 1 second.

LSDB changes result in SPF calculations. When the topology changes frequently, a large amount of network and router resources are occ up ied by SPF calculat ion. You can adjust the SPF c alc ulat io n interval to reduce the impact.

For a stable network, the minimum interval is used. If network changes becom e frequent, the SPF calculation interval is incre mented by the incremental inte rval × 2 maximum interval is reached. The value n is the number of calculation times.

To set the SPF calculation interval:

1. Enter system view.

2. Enter OSPF view.

system-view ospf [

router-id | vpn-instance-name ] *

process-id |

router-id

vpn-instance

n-2

for each c alculation until the

N/A

Step

Command

Remarks

Set the SPF

interval is 5

minimum interval is 50

The incremental interval is 200

Step

Command

Remarks

The default setting is 1000

Step

Command

Remarks

Set the LSA

The maximum interval is 5

interval is 50

calculation interval.

spf-schedule-interval

maximum-interval [ minimum-interval [ incremental-interval ] ]

Setting the LSA arrival interval

If OSPF receives an LSA that has the same LSA type, LS ID, and router ID as the previously received LSA within the LSA arrival interval, OSPF discards the LSA to save bandwidth and route resources.

To set the LSA arrival interval:

By default:

• The maximum seconds.

• The milliseconds.

• milliseconds.

1. Enter system view.

2. Enter OSPF view.

3. Set the LSA arrival interval.

system-view ospf [

router-id | vpn-instance-name ] *

lsa-arrival-interval

process-id |

vpn-instance

interval

Setting the LSA generation interval

Adjust the LSA generation interval to protect network resources and routers from being overwhelmed by LSAs at the time of frequent network changes.

For a stable network, the minimum interval is us ed. If network changes becom e frequent, the LSA generation interval is increm ented by the incremental inter val × 2 maximum interval is reached. The value n is the number of generation times.

To set the LSA generation interval:

router-id

N/A

milliseconds. Make sure this interval is smaller

than or equal to the interval set with

lsa-generation-interva

the command.

n-2

for each generation until the

1. Enter system view.

2. Enter OSPF view.

generation interval.

system-view ospf [

process-id |

vpn-instance

lsa-generation-interval

maximum-interval [ minimum-interval [ incremental-interval ] ]

router-id

vpn-instance-name ] *

router-id |

N/A

By default:

• seconds.

• The minimum milliseconds.

• The incremental interval is 200 milliseconds.

Step

Command

Remarks

Disable interfaces from receiving and sending

disables only the interfaces

with the current

process rather than other processes can disable the same

Step

Command

Remarks

is not

stub router is not related to a

Disabling interf aces from receivin g and sending OSPF packets

T o enhance OSPF adaptability and reduce resource consumption, you can set an OSPF interface to "silent." A silent OSPF interface blocks OSPF packets and cannot es tablish any OSPF neighbor relationship. However, other interfaces on the router can still advertise direct routes of the interface in Router LSAs.

To disable interfaces from receiving and sending routing information:

1. Enter system view.

2. Enter OSPF view.

OSPF packets.

system-view ospf [

router-id | vpn-instance-name ] *

silent-interface

interface-number |

Configuring stub routers

A stub router is used for traffic control. It repor ts its status as a stub router to neig hboring OSPF routers. The neighbor ing routers can h ave a route to the stub router, but they do not us e the stub router to forward data.

Router LSAs from the stub router might contain different link type values. A value of 3 means a link to a stub network, and the c os t of the link will not be cha nged b y def ault. To set the cost of the link to 65535, specify the include-stub keyword in the stub-router command. A value of 1, 2 or 4 means a point-to-point link, a link to a transit network, or a virtual link. On such links, a maximum cost value of 65535 is used. Neighbors do not send packets to the stub router as long as they have a route with a smaller cost.

process-id |

vpn-instance

{ interface-type

all

}

router-id

N/A

By default, an OSPF interfa ce can receive and send OSPF packets.

silent-interface

The associated processes. Multiple OSPF interface from receiving and

sending OSPF packets.

command

To configure a router as a stub router:

1. Enter system view.

2. Enter OSPF view.

3. Configure the router as

a stub router.

system-view ospf [

process-id |

vpn-instance stub-router

[ max-metric-value ] |

on-startup

[ seconds ] } | [ max-metric-value ] ] *

router-id

vpn-instance-name ] *

[

{ seconds |

router-id |

external-lsa

include-stub

wait-for-bgp

summary-lsa

N/A

By default, the router

configured as a stub router. A

stub area.

Step

Command

Remarks

system-view

Configure area

For information about

Step

Command

Remarks

Configure interface

authentication is

Configuring OSPF authentication

Perform this task to configure OSPF ar ea and int erf ac e authentication. OSPF adds the configured key into sent packets, and uses the key to authenticate received packets.

Only p ackets that pass the authentication can be received. If a pack et fails the authentication, the OSPF neighbor relationship cannot be established.

If you configure OS PF authentication for bot h an area and an interface in that area, the i nterface uses the OSPF authentication configured on it.

Configuring OSPF area authentication

You must configure the same authentication mode and key on all the routers in an area. To configure OSPF area au thent ic at ion:

1. Enter system view.

2. Enter OSPF view.

3. Enter area view.

authentication mode.

ospf [ vpn-instance

area

area-id

• Configure MD5 authentication:

authentication-mode { hmac-md5 | md5 } key-id { cipher | plain } string

• Configure simple authentication:

authentication-mode simple { cipher | plain } string

• Configure keychain authentication:

authentication-mode keychain

keychain-name

Configuring OSPF interface authentication

You must configure the sa me authent ication m ode and k ey on both the local interface and its peer interface.

To configure OSPF interface authentication:

1. Enter system view.

2. Enter interface view.

authentication mode.

system-view interface

• Configure simple authentication:

ospf authentication-mode simple { cipher | plain } string

• Configure MD5 authentication: ospf authentication-mode { hmac-md5 | md5 } key-id { cipher | plain } string

• Configure keychain authentication: ospf authentication-mode keychain

keychain-name

process-id |

vpn-instance-name ] *

interface-type interface-number

router-id

router-id |

N/A

By default, no authentication is configured.

keychains, see Security Configuration Guide.

N/A N/A

By default, no configured.

For information about keychain, see Security Configuration Guide.

HP FlexFabric 12900E Layer 3—IP Routing Configuration Guide

Specifications and Main Features

Frequently Asked Questions

User Manual

Contents

Configuring basic IP routing

Routing table

Dynamic routing protocols

Route preference

Load sharing

Route backup

Route recursion

Route redistribution

Extension attribute redistribution

Setting the maximum lifetime for routes and labels in the RIB

Setting the maximum lifetime for routes in the FIB

Configuring RIB NSR

Configuring IP v4 RIB NSR

Configuring IP v6 RIB NSR

Configuring inter-protocol FRR

Configuring IP v4 RIB inter-protoc ol FRR

Configuring IP v6 RIB inter-protoc ol FRR

Enabling the IPv4 enhanced ECMP mode

Displaying and maintaining a routing table

Configuring static routing

Configuring a static route

Configuring BFD for static routes

Bidirectional c ontrol mode

Single-hop echo mode

Configuring static route FRR

Configuration guidelines

Configuring static route FRR by specifying a backup next hop

Configuring static route FRR to automatically select a backup next hop

Enabling BFD echo packet mode for static route FRR

Displaying and maintaining static routes

Static route configuration examples

Basic static route configuration example

BFD for static routes configuration ex am ple (direct next hop)

BFD for static routes configuration ex am ple (indirect next hop)

Static route FRR configuration example

Configuring a default route

Configuring RIP

Overview

RIP route entries

Routing loop prevention

RIP operation

RIP versions

Protocols and standards

RIP configuration task list

Configuring basic RIP

Enabling RIP

Controlling RIP reception and adverti sement on interfaces

Configuring a RIP version

Configuring RIP route control

Configuring an add i tional routing metric

Configuring RI P v2 route summarization

Disabling host r oute reception

Advertising a def ault route

Configuring received/redistributed route filtering

Setting a preference for RIP

Configuring RI P route redistribution

Tuning and optimizing RIP networks

Configuration prerequisites

Setting RIP timers

Enabling split horizon and poison reverse

Setting the maxim um number of RIP ECMP routes

Enabling zero field check on incoming RIPv1 messages

Enabling source IP address check on incoming RIP updates

Configuring RI P v2 message authent i c ation

Setting the RIP t riggered update inter v al

Specifying a RIP nei ghbor

Configuring RI P network management

Configuring the RIP packet sending rat e

Setting the maximum l ength of RIP packet s

Setting the DSCP value for outgoing RIP packets

Configuring RIP GR

Enabling RIP NSR

Configuring BFD for RIP

Configuring single-hop echo detection (for a direct l y connected RIP neighbor)

Configuring single-hop echo detection (for a specifi c destination)