Concept Guide

Conguring Passive Peering...................................................................................................................................209
Maintaining Existing AS Numbers During an AS Migration.................................................................................210
Allowing an AS Number to Appear in its Own AS Path........................................................................................211
Enabling Graceful Restart........................................................................................................................................212
Filtering on an AS-Path Attribute........................................................................................................................... 213
Regular Expressions as Filters.................................................................................................................................214
Redistributing Routes...............................................................................................................................................215
Redistributing iBGP Routes into IGP......................................................................................................................216
Enabling Additional Paths........................................................................................................................................ 219
Conguring IP Community Lists............................................................................................................................. 219
Conguring an IP Extended Community List........................................................................................................ 221
Filtering Routes with Community Lists.................................................................................................................. 221
Manipulating the COMMUNITY Attribute............................................................................................................ 222
Changing MED Attributes.......................................................................................................................................224
Changing the LOCAL_PREFERENCE Attribute..................................................................................................224
Conguring the local System or a Dierent System to be the Next Hop for BGP-Learned Routes............ 225
Changing the WEIGHT Attribute...........................................................................................................................225
Enabling Multipath...................................................................................................................................................226
Route Reectors......................................................................................................................................................226
Conguring BGP Confederations.......................................................................................................................... 228
Enabling Route Flap Dampening............................................................................................................................ 228
Changing BGP keepalive and hold timers.............................................................................................................230
Setting the extended timer..................................................................................................................................... 231
Enabling or disabling BGP neighbors.....................................................................................................................232
Route Map Continue............................................................................................................................................... 233
Enabling MBGP Congurations....................................................................................................................................234
MBGP support for IPv6................................................................................................................................................234
Conguring IPv6 MBGP between peers.....................................................................................................................234
Example-Conguring IPv4 and IPv6 neighbors......................................................................................................... 235
Congure IPv6 NH Automatically for IPv6 Prex Advertised over IPv4 Neighbor................................................237
BGP Regular Expression Optimization........................................................................................................................239
Debugging BGP............................................................................................................................................................. 239
Storing Last and Bad PDUs....................................................................................................................................240
Capturing PDUs........................................................................................................................................................241
PDU Counters.......................................................................................................................................................... 242
10 Content Addressable Memory (CAM).......................................................................................................243
CAM Allocation...............................................................................................................................................................243
Test CAM Usage............................................................................................................................................................245
View CAM-ACL Settings.............................................................................................................................................. 245
View CAM Usage........................................................................................................................................................... 247
Conguring CAM Threshold and Silence Period........................................................................................................ 247
Setting CAM Threshold and Silence Period..........................................................................................................247
CAM Optimization......................................................................................................................................................... 248
Troubleshoot CAM Proling..........................................................................................................................................248
QoS CAM Region Limitation...................................................................................................................................248
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