Congure BFD for OSPFv3.....................................................................................................................................152
Congure BFD for IS-IS...........................................................................................................................................155
Congure BFD for BGP...........................................................................................................................................158
Congure BFD for VRRP.........................................................................................................................................164
Conguring Protocol Liveness................................................................................................................................ 167
Troubleshooting BFD................................................................................................................................................ 167
Establishing Sessions for Static Routes.................................................................................................................168
9 Border Gateway Protocol IPv4 (BGPv4)..................................................................................................... 171
Autonomous Systems (AS)............................................................................................................................................171
Sessions and Peers.........................................................................................................................................................173
Establish a Session................................................................................................................................................... 173
Route Reectors............................................................................................................................................................. 174
BGP Attributes................................................................................................................................................................175
Best Path Selection Criteria....................................................................................................................................175
Weight........................................................................................................................................................................ 177
Local Preference....................................................................................................................................................... 177
Multi-Exit Discriminators (MEDs)...........................................................................................................................178
Origin..........................................................................................................................................................................179
AS Path......................................................................................................................................................................180
Next Hop................................................................................................................................................................... 180
Multiprotocol BGP..........................................................................................................................................................180
Implement BGP with Dell Networking OS....................................................................................................................181
Additional Path (Add-Path) Support.......................................................................................................................181
Advertise IGP Cost as MED for Redistributed Routes......................................................................................... 181
Ignore Router-ID in Best-Path Calculation............................................................................................................ 182
Four-Byte AS Numbers............................................................................................................................................182
AS4 Number Representation.................................................................................................................................. 182
AS Number Migration.............................................................................................................................................. 184
BGP4 Management Information Base (MIB)........................................................................................................185
Important Points to Remember..............................................................................................................................185
Conguration Information..............................................................................................................................................186
BGP Conguration......................................................................................................................................................... 186
Enabling BGP.............................................................................................................................................................187
Conguring AS4 Number Representations...........................................................................................................190
Conguring Peer Groups.........................................................................................................................................192
Conguring BGP Fast Fall-Over.............................................................................................................................194
Conguring Passive Peering................................................................................................................................... 196
Maintaining Existing AS Numbers During an AS Migration.................................................................................196
Allowing an AS Number to Appear in its Own AS Path....................................................................................... 197
Enabling Graceful Restart........................................................................................................................................198
Enabling Neighbor Graceful Restart...................................................................................................................... 199
Enabling or disabling BGP neighbors..................................................................................................................... 199
Filtering on an AS-Path Attribute........................................................................................................................... 201
Regular Expressions as Filters................................................................................................................................202
Redistributing Routes..............................................................................................................................................203
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