Congure BFD................................................................................................................................................................ 149
Congure BFD for Physical Ports.......................................................................................................................... 150
Congure BFD for Static Routes.............................................................................................................................151
Congure BFD for OSPF.........................................................................................................................................154
Congure BFD for OSPFv3.....................................................................................................................................157
Congure BFD for IS-IS...........................................................................................................................................158
Congure BFD for BGP...........................................................................................................................................160
Congure BFD for VRRP.........................................................................................................................................167
Conguring Protocol Liveness................................................................................................................................ 170
Troubleshooting BFD................................................................................................................................................170
9 Border Gateway Protocol IPv4 (BGPv4).....................................................................................................172
Autonomous Systems (AS)........................................................................................................................................... 172
Sessions and Peers.........................................................................................................................................................174
Establish a Session....................................................................................................................................................174
Route Reectors.............................................................................................................................................................175
BGP Attributes................................................................................................................................................................176
Best Path Selection Criteria.................................................................................................................................... 176
Weight........................................................................................................................................................................178
Local Preference....................................................................................................................................................... 178
Multi-Exit Discriminators (MEDs)...........................................................................................................................179
Origin..........................................................................................................................................................................180
AS Path.......................................................................................................................................................................181
Next Hop....................................................................................................................................................................181
Multiprotocol BGP...........................................................................................................................................................181
Implement BGP with Dell Networking OS...................................................................................................................182
Additional Path (Add-Path) Support......................................................................................................................182
Advertise IGP Cost as MED for Redistributed Routes........................................................................................ 182
Ignore Router-ID in Best-Path Calculation............................................................................................................ 183
Four-Byte AS Numbers............................................................................................................................................183
AS4 Number Representation.................................................................................................................................. 183
AS Number Migration.............................................................................................................................................. 185
BGP4 Management Information Base (MIB)........................................................................................................186
Important Points to Remember.............................................................................................................................. 186
Conguration Information..............................................................................................................................................187
BGP Conguration..........................................................................................................................................................187
Enabling BGP............................................................................................................................................................ 188
Conguring AS4 Number Representations............................................................................................................191
Conguring Peer Groups.........................................................................................................................................193
Conguring BGP Fast Fall-Over.............................................................................................................................195
Conguring Passive Peering....................................................................................................................................197
Maintaining Existing AS Numbers During an AS Migration................................................................................. 197
Allowing an AS Number to Appear in its Own AS Path.......................................................................................198
Enabling Graceful Restart....................................................................................................................................... 199
Enabling Neighbor Graceful Restart......................................................................................................................200
Filtering on an AS-Path Attribute.......................................................................................................................... 200
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