Users Guide

Configure BFD for IS-IS...........................................................................................................................................154
Configure BFD for BGP...........................................................................................................................................156
Configure BFD for VRRP........................................................................................................................................ 163
Configuring Protocol Liveness................................................................................................................................166
Troubleshooting BFD............................................................................................................................................... 166
9 Border Gateway Protocol IPv4 (BGPv4)....................................................................................................168
Autonomous Systems (AS)...........................................................................................................................................168
Sessions and Peers........................................................................................................................................................ 170
Establish a Session................................................................................................................................................... 170
Route Reflectors............................................................................................................................................................. 171
BGP Attributes................................................................................................................................................................172
Best Path Selection Criteria....................................................................................................................................173
Weight........................................................................................................................................................................174
Local Preference.......................................................................................................................................................174
Multi-Exit Discriminators (MEDs).......................................................................................................................... 175
Origin..........................................................................................................................................................................176
AS Path......................................................................................................................................................................177
Next Hop....................................................................................................................................................................177
Multiprotocol BGP..........................................................................................................................................................177
Implement BGP with Dell Networking OS...................................................................................................................178
Additional Path (Add-Path) Support..................................................................................................................... 178
Advertise IGP Cost as MED for Redistributed Routes........................................................................................178
Ignore Router-ID in Best-Path Calculation............................................................................................................179
Four-Byte AS Numbers........................................................................................................................................... 179
AS4 Number Representation.................................................................................................................................. 179
AS Number Migration...............................................................................................................................................181
BGP4 Management Information Base (MIB)....................................................................................................... 182
Important Points to Remember..............................................................................................................................182
Configuration Information............................................................................................................................................. 183
BGP Configuration......................................................................................................................................................... 183
Enabling BGP............................................................................................................................................................ 184
Configuring AS4 Number Representations...........................................................................................................187
Configuring Peer Groups.........................................................................................................................................189
Configuring BGP Fast Fall-Over..............................................................................................................................191
Configuring Passive Peering................................................................................................................................... 193
Maintaining Existing AS Numbers During an AS Migration.................................................................................193
Allowing an AS Number to Appear in its Own AS Path.......................................................................................194
Enabling Graceful Restart....................................................................................................................................... 195
Enabling Neighbor Graceful Restart...................................................................................................................... 196
Filtering on an AS-Path Attribute...........................................................................................................................196
Regular Expressions as Filters................................................................................................................................ 198
Redistributing Routes.............................................................................................................................................. 199
Enabling Additional Paths....................................................................................................................................... 200
Configuring IP Community Lists............................................................................................................................200
Configuring an IP Extended Community List........................................................................................................201
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