Users Guide

Four-Byte AS Numbers....................................................................................................218
AS4 Number Representation..........................................................................................218
AS Number Migration............................................................................................................220
BGP4 Management Information Base (MIB).....................................................................222
Important Points to Remember.................................................................................... 222
Configuration Information................................................................................................... 223
BGP Configuration........................................................................................................... 223
Enabling BGP.......................................................................................................................... 224
Configuring AS4 Number Representations...................................................................... 228
Configuring Peer Groups..................................................................................................... 230
Configuring BGP Fast Fall-Over..........................................................................................233
Configuring Passive Peering................................................................................................234
Maintaining Existing AS Numbers During an AS Migration............................................235
Allowing an AS Number to Appear in its Own AS Path..................................................236
Enabling Graceful Restart..................................................................................................... 237
Enabling Neighbor Graceful Restart.................................................................................. 238
Filtering on an AS-Path Attribute........................................................................................239
Regular Expressions as Filters........................................................................................240
Filtering BGP Routes Using AS-PATH Information......................................................... 242
Redistributing Routes............................................................................................................ 243
Enabling Additional Paths.....................................................................................................244
Configuring IP Community Lists.........................................................................................244
Filtering Routes with Community Lists............................................................................. 246
Manipulating the COMMUNITY Attribute......................................................................... 246
Changing MED Attributes.....................................................................................................248
Changing the LOCAL_PREFERENCE Attribute................................................................248
Changing the NEXT_HOP Attribute...................................................................................249
Changing the WEIGHT Attribute.........................................................................................250
Enabling Multipath.................................................................................................................250
Filtering BGP Routes Using Route Maps............................................................................251
Filtering BGP Routes Using AS-PATH Information..........................................................251
Filtering BGP Routes..............................................................................................................252
Filtering BGP Routes Using Route Maps..................................................................... 254
Filtering BGP Routes Using AS-PATH Information....................................................255
Configuring BGP Route Reflectors.....................................................................................255
Aggregating Routes............................................................................................................... 256
Configuring BGP Confederations.......................................................................................257
Enabling Route Flap Dampening........................................................................................ 257
Changing BGP Timers...........................................................................................................260
Enabling BGP Neighbor Soft-Reconfiguration................................................................ 261
Route Map Continue............................................................................................................. 262
Match a Clause with a Continue Clause..................................................................... 262
9