Users Guide

Multi-Exit Discriminators (MEDs)........................................................................................................................... 161
Origin..........................................................................................................................................................................162
AS Path......................................................................................................................................................................163
Next Hop................................................................................................................................................................... 163
Multiprotocol BGP..........................................................................................................................................................163
Implement BGP with Dell Networking OS...................................................................................................................164
Additional Path (Add-Path) Support..................................................................................................................... 164
Advertise IGP Cost as MED for Redistributed Routes........................................................................................164
Ignore Router-ID in Best-Path Calculation........................................................................................................... 165
Four-Byte AS Numbers...........................................................................................................................................165
AS4 Number Representation..................................................................................................................................165
AS Number Migration.............................................................................................................................................. 167
BGP4 Management Information Base (MIB)....................................................................................................... 168
Important Points to Remember..............................................................................................................................168
Configuration Information............................................................................................................................................. 169
BGP Configuration......................................................................................................................................................... 169
Enabling BGP............................................................................................................................................................ 170
Configuring AS4 Number Representations...........................................................................................................173
Configuring Peer Groups.........................................................................................................................................175
Configuring BGP Fast Fall-Over............................................................................................................................. 177
Configuring Passive Peering................................................................................................................................... 179
Maintaining Existing AS Numbers During an AS Migration.................................................................................179
Allowing an AS Number to Appear in its Own AS Path.......................................................................................180
Enabling Graceful Restart........................................................................................................................................ 181
Enabling Neighbor Graceful Restart...................................................................................................................... 182
Filtering on an AS-Path Attribute...........................................................................................................................182
Regular Expressions as Filters................................................................................................................................ 184
Redistributing Routes.............................................................................................................................................. 185
Enabling Additional Paths........................................................................................................................................186
Configuring IP Community Lists.............................................................................................................................186
Configuring an IP Extended Community List........................................................................................................187
Filtering Routes with Community Lists..................................................................................................................188
Manipulating the COMMUNITY Attribute.............................................................................................................189
Changing MED Attributes.......................................................................................................................................190
Changing the LOCAL_PREFERENCE Attribute..................................................................................................190
Configuring the local System or a Different System to be the Next Hop for BGP-Learned Routes.............191
Changing the WEIGHT Attribute............................................................................................................................192
Enabling Multipath....................................................................................................................................................192
Filtering BGP Routes............................................................................................................................................... 192
Filtering BGP Routes Using Route Maps.............................................................................................................. 194
Filtering BGP Routes Using AS-PATH Information............................................................................................. 194
Configuring BGP Route Reflectors........................................................................................................................195
Aggregating Routes................................................................................................................................................. 196
Configuring BGP Confederations...........................................................................................................................196
Enabling Route Flap Dampening.............................................................................................................................197
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