Users Guide

Weight........................................................................................................................................................................ 161
Local Preference........................................................................................................................................................161
Multi-Exit Discriminators (MEDs)...........................................................................................................................162
Origin..........................................................................................................................................................................163
AS Path......................................................................................................................................................................163
Next Hop................................................................................................................................................................... 164
Multiprotocol BGP..........................................................................................................................................................164
Implement BGP with Dell Networking OS...................................................................................................................165
Additional Path (Add-Path) Support......................................................................................................................165
Advertise IGP Cost as MED for Redistributed Routes........................................................................................ 165
Ignore Router-ID in Best-Path Calculation............................................................................................................ 166
Four-Byte AS Numbers........................................................................................................................................... 166
AS4 Number Representation.................................................................................................................................. 166
AS Number Migration.............................................................................................................................................. 168
BGP4 Management Information Base (MIB)........................................................................................................169
Important Points to Remember.............................................................................................................................. 169
Conguration Information..............................................................................................................................................170
BGP Conguration..........................................................................................................................................................170
Enabling BGP............................................................................................................................................................. 171
Conguring AS4 Number Representations............................................................................................................174
Conguring Peer Groups......................................................................................................................................... 175
Conguring BGP Fast Fall-Over............................................................................................................................. 178
Conguring Passive Peering....................................................................................................................................179
Maintaining Existing AS Numbers During an AS Migration.................................................................................180
Allowing an AS Number to Appear in its Own AS Path........................................................................................181
Enabling Graceful Restart........................................................................................................................................182
Enabling Neighbor Graceful Restart.......................................................................................................................183
Filtering on an AS-Path Attribute........................................................................................................................... 183
Regular Expressions as Filters.................................................................................................................................184
Redistributing Routes...............................................................................................................................................186
Enabling Additional Paths........................................................................................................................................ 186
Conguring IP Community Lists............................................................................................................................. 187
Conguring an IP Extended Community List........................................................................................................188
Filtering Routes with Community Lists..................................................................................................................189
Manipulating the COMMUNITY Attribute.............................................................................................................189
Changing MED Attributes........................................................................................................................................ 191
Changing the LOCAL_PREFERENCE Attribute................................................................................................... 191
Conguring the local System or a Dierent System to be the Next Hop for BGP-Learned Routes............. 192
Changing the WEIGHT Attribute............................................................................................................................192
Enabling Multipath....................................................................................................................................................193
Filtering BGP Routes................................................................................................................................................193
Filtering BGP Routes Using Route Maps...............................................................................................................194
Filtering BGP Routes Using AS-PATH Information.............................................................................................. 195
Conguring BGP Route Reectors........................................................................................................................ 196
Aggregating Routes..................................................................................................................................................196
Conguring BGP Confederations........................................................................................................................... 197
Enabling Route Flap Dampening............................................................................................................................. 197
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