Administrator Guide
Congure BFD for VRRP.........................................................................................................................................168
Conguring Protocol Liveness.................................................................................................................................171
Troubleshooting BFD.................................................................................................................................................171
8 Border Gateway Protocol IPv4 (BGPv4).....................................................................................................173
Autonomous Systems (AS)........................................................................................................................................... 173
Sessions and Peers.........................................................................................................................................................175
Establish a Session................................................................................................................................................... 175
Route Reectors.............................................................................................................................................................176
BGP Attributes................................................................................................................................................................177
Best Path Selection Criteria.................................................................................................................................... 177
Weight........................................................................................................................................................................179
Local Preference....................................................................................................................................................... 179
Multi-Exit Discriminators (MEDs)...........................................................................................................................180
Origin...........................................................................................................................................................................181
AS Path......................................................................................................................................................................182
Next Hop................................................................................................................................................................... 182
Multiprotocol BGP..........................................................................................................................................................182
Implement BGP with Dell Networking OS...................................................................................................................183
Additional Path (Add-Path) Support......................................................................................................................183
Advertise IGP Cost as MED for Redistributed Routes........................................................................................ 183
Ignore Router-ID in Best-Path Calculation............................................................................................................ 184
Four-Byte AS Numbers............................................................................................................................................184
AS4 Number Representation.................................................................................................................................. 184
AS Number Migration.............................................................................................................................................. 186
BGP4 Management Information Base (MIB)........................................................................................................187
Important Points to Remember...............................................................................................................................187
Conguration Information..............................................................................................................................................188
BGP Conguration......................................................................................................................................................... 188
Enabling BGP............................................................................................................................................................ 189
Conguring AS4 Number Representations........................................................................................................... 192
Conguring Peer Groups.........................................................................................................................................194
Conguring BGP Fast Fall-Over.............................................................................................................................196
Conguring Passive Peering................................................................................................................................... 198
Maintaining Existing AS Numbers During an AS Migration.................................................................................198
Allowing an AS Number to Appear in its Own AS Path.......................................................................................199
Enabling Graceful Restart.......................................................................................................................................200
Enabling Neighbor Graceful Restart...................................................................................................................... 201
Filtering on an AS-Path Attribute........................................................................................................................... 201
Regular Expressions as Filters................................................................................................................................203
Redistributing Routes..............................................................................................................................................204
Enabling Additional Paths....................................................................................................................................... 205
Conguring IP Community Lists............................................................................................................................ 205
Conguring an IP Extended Community List....................................................................................................... 206
Filtering Routes with Community Lists................................................................................................................. 207
Manipulating the COMMUNITY Attribute............................................................................................................208
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