HP 6125XLG R2306-HP 6125XLG Blade Switch Layer 3 - IP Routing Configuration Gu - Page 43

Configuring BFD for RIP, Configuring RIP FRR

Page 43 highlights

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. With the GR feature, the restarting router (known as the "GR Restarter") can notify the event to its GR capable neighbors. GR capable neighbors (known as "GR Helpers") keep their 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: Step 1. Enter system view. 2. Enable RIP and enter RIP view. 3. Enable GR for RIP. Command system-view rip [ process-id ] [ vpn-instance vpn-instance-name ] graceful-restart Remarks N/A N/A By default, RIP GR is disabled. Configuring BFD for RIP RIP detects route failures by periodically sending requests. If it receives no response for a route within a certain time, RIP considers the route unreachable. This detection mechanism is not fast enough. To speed up convergence, perform this task to enable BFD for RIP. For more information about BFD, see High Availability Configuration Guide. BFD provides only single-hop echo detection mode for directly connected RIP neighbors. In this mode, a BFD session is established only when the neighbor has route information to send. To enable BFD for RIP (single-hop echo detection): Step 1. Enter system view. Command system-view 2. Configure the source IP address of BFD echo packets. bfd echo-source-ip ip-address 3. Enter interface view. 4. Enable BFD for RIP. interface interface-type interface-number rip bfd enable Remarks N/A By default, the source IP address of BFD echo packets is not configured. N/A By default, BFD for RIP is disabled. Configuring RIP FRR A link or router failure on a path can cause packet loss and even routing loop until RIP completes routing convergence based on the new network topology. FRR uses BFD to detect failures and enables fast rerouting to minimize the impact of link or node failures. 32

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
  • 154
  • 155
  • 156
  • 157
  • 158
  • 159
  • 160
  • 161
  • 162
  • 163
  • 164
  • 165
  • 166
  • 167
  • 168
  • 169
  • 170
  • 171
  • 172
  • 173
  • 174
  • 175
  • 176
  • 177
  • 178
  • 179
  • 180
  • 181
  • 182
  • 183
  • 184
  • 185
  • 186
  • 187
  • 188
  • 189
  • 190
  • 191
  • 192
  • 193
  • 194
  • 195
  • 196
  • 197
  • 198
  • 199
  • 200
  • 201
  • 202
  • 203
  • 204
  • 205
  • 206
  • 207
  • 208
  • 209
  • 210
  • 211
  • 212
  • 213
  • 214
  • 215
  • 216
  • 217
  • 218
  • 219
  • 220
  • 221
  • 222
  • 223
  • 224
  • 225
  • 226
  • 227
  • 228
  • 229
  • 230
  • 231
  • 232
  • 233
  • 234
  • 235
  • 236
  • 237
  • 238
  • 239
  • 240
  • 241
  • 242
  • 243
  • 244
  • 245
  • 246
  • 247
  • 248
  • 249
  • 250
  • 251
  • 252
  • 253
  • 254
  • 255
  • 256
  • 257
  • 258
  • 259
  • 260
  • 261
  • 262
  • 263
  • 264
  • 265
  • 266
  • 267
  • 268
  • 269
  • 270
  • 271
  • 272
  • 273
  • 274
  • 275
  • 276
  • 277
  • 278
  • 279
  • 280
  • 281
  • 282
  • 283
  • 284
  • 285
  • 286
  • 287
  • 288
  • 289
  • 290
  • 291
  • 292
  • 293
  • 294
  • 295
  • 296
  • 297
  • 298
  • 299
  • 300
  • 301
  • 302
  • 303
  • 304
  • 305
  • 306
  • 307
  • 308
  • 309
  • 310
  • 311
  • 312
  • 313
  • 314
  • 315
  • 316
  • 317
  • 318
  • 319
  • 320
  • 321
  • 322
  • 323
  • 324
  • 325
  • 326
  • 327
  • 328
  • 329
  • 330
  • 331
  • 332
  • 333
  • 334
  • 335
  • 336
  • 337
  • 338
  • 339
  • 340
  • 341
  • 342
  • 343
  • 344
  • 345
  • 346
  • 347
  • 348
  • 349
  • 350
  • 351
  • 352
  • 353
  • 354
  • 355
  • 356
  • 357
  • 358
  • 359
  • 360
  • 361
  • 362
  • 363
  • 364
  • 365
  • 366
  • 367
  • 368
  • 369
  • 370
  • 371
  • 372
  • 373
  • 374
  • 375
  • 376
  • 377
  • 378
  • 379
  • 380
  • 381
  • 382
  • 383
  • 384
  • 385
  • 386
  • 387
  • 388
  • 389
  • 390
  • 391
  • 392
  • 393
  • 394
  • 395
  • 396
  • 397
  • 398
  • 399
  • 400
  • 401
  • 402
  • 403
  • 404
  • 405
  • 406
  • 407
  • 408
  • 409
  • 410
  • 411
  • 412
  • 413
  • 414

32
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.
With the GR feature, the restarting router (known as the "GR Restarter") can notify the event to its GR
capable neighbors. GR capable neighbors (known as "GR Helpers") keep their 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:
Step
Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enable RIP and enter RIP
view.
rip
[
process-id
] [
vpn-instance
vpn-instance-name
]
N/A
3.
Enable GR for RIP.
graceful-restart
By default, RIP GR is disabled.
Configuring BFD for RIP
RIP detects route failures by periodically sending requests. If it receives no response for a route within a
certain time, RIP considers the route unreachable. This detection mechanism is not fast enough. To speed
up convergence, perform this task to enable BFD for RIP. For more information about BFD, see
High
Availability Configuration Guide
.
BFD provides only single-hop echo detection mode for directly connected RIP neighbors. In this mode, a
BFD session is established only when the neighbor has route information to send.
To enable BFD for RIP (single-hop echo detection):
Step
Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Configure the source IP
address of BFD echo packets.
bfd echo-source-ip
ip-address
By default, the source IP address of
BFD echo packets is not
configured.
3.
Enter interface view.
interface
interface-type
interface-number
N/A
4.
Enable BFD for RIP.
rip bfd enable
By default, BFD for RIP is disabled.
Configuring RIP FRR
A link or router failure on a path can cause packet loss and even routing loop until RIP completes routing
convergence based on the new network topology. FRR uses BFD to detect failures and enables fast
rerouting to minimize the impact of link or node failures.