Concept Guide

Route-refresh and Soft-reconguration............................................................................................................... 204
Aggregating Routes................................................................................................................................................. 207
Filtering BGP Routes............................................................................................................................................... 207
Filtering BGP Routes Using Route Maps..............................................................................................................207
Filtering BGP Routes Using AS-PATH Information............................................................................................. 208
Conguring Peer Groups........................................................................................................................................ 209
Conguring BGP Fast Fall-Over............................................................................................................................. 217
Conguring Passive Peering................................................................................................................................... 218
Maintaining Existing AS Numbers During an AS Migration.................................................................................219
Allowing an AS Number to Appear in its Own AS Path...................................................................................... 220
Enabling Graceful Restart........................................................................................................................................221
Filtering on an AS-Path Attribute...........................................................................................................................222
Regular Expressions as Filters................................................................................................................................ 223
Redistributing Routes..............................................................................................................................................224
Redistributing iBGP Routes into IGP.....................................................................................................................225
Enabling Additional Paths........................................................................................................................................228
Conguring IP Community Lists............................................................................................................................ 228
Conguring an IP Extended Community List....................................................................................................... 230
Filtering Routes with Community Lists................................................................................................................. 230
Manipulating the COMMUNITY Attribute.............................................................................................................231
Changing MED Attributes.......................................................................................................................................233
Changing the LOCAL_PREFERENCE Attribute..................................................................................................233
Conguring the local System or a Dierent System to be the Next Hop for BGP-Learned Routes.............234
Changing the WEIGHT Attribute........................................................................................................................... 234
Enabling Multipath...................................................................................................................................................235
Route Reectors......................................................................................................................................................235
Conguring BGP Confederations...........................................................................................................................237
Enabling Route Flap Dampening............................................................................................................................ 237
Changing BGP keepalive and hold timers.............................................................................................................239
Setting the extended timer.................................................................................................................................... 240
Enabling or disabling BGP neighbors......................................................................................................................241
Route Map Continue............................................................................................................................................... 242
Enabling MBGP Congurations....................................................................................................................................243
MBGP support for IPv6................................................................................................................................................ 243
Conguring IPv6 MBGP between peers.....................................................................................................................243
Example-Conguring IPv4 and IPv6 neighbors......................................................................................................... 244
Congure IPv6 NH Automatically for IPv6 Prex Advertised over IPv4 Neighbor............................................... 246
BGP Regular Expression Optimization........................................................................................................................248
Debugging BGP..............................................................................................................................................................248
Storing Last and Bad PDUs....................................................................................................................................249
Capturing PDUs.......................................................................................................................................................250
PDU Counters...........................................................................................................................................................251
10 Content Addressable Memory (CAM).......................................................................................................252
CAM Allocation...............................................................................................................................................................252
Test CAM Usage............................................................................................................................................................254
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