Users Guide

Congure BFD for IS-IS...........................................................................................................................................159
Congure BFD for BGP............................................................................................................................................161
Congure BFD for VRRP.........................................................................................................................................169
Conguring Protocol Liveness.................................................................................................................................171
9 Border Gateway Protocol (BGP).................................................................................................................172
Border Gateway Protocol version 4 (BGPv4).............................................................................................................172
Autonomous Systems (AS)........................................................................................................................................... 172
AS4 Number Representation...................................................................................................................................174
Four-Byte AS Numbers............................................................................................................................................176
Multiprotocol BGP..........................................................................................................................................................176
MBGP for IPv4 MulticastBGP Address Family modelIPv4 and IPv6 address family........................................177
Sessions and Peers.........................................................................................................................................................177
Establish a Session....................................................................................................................................................177
Implementing BGP global and address family............................................................................................................. 178
BGP global conguration default values................................................................................................................179
BGP Attributes for selecting Best Path.......................................................................................................................179
Best Path Selection Criteria....................................................................................................................................180
Weight.........................................................................................................................................................................181
Local Preference.......................................................................................................................................................182
Multi-Exit Discriminators (MEDs)...........................................................................................................................182
Origin..........................................................................................................................................................................183
AS Path......................................................................................................................................................................184
Next Hop................................................................................................................................................................... 184
Implement BGP with Dell EMC Networking OS.........................................................................................................185
Additional Path (Add-Path) Support......................................................................................................................185
Advertise IGP Cost as MED for Redistributed Routes........................................................................................ 185
Ignore Router-ID in Best-Path Calculation............................................................................................................ 186
AS Number Migration.............................................................................................................................................. 186
BGP4 Management Information Base (MIB)........................................................................................................187
Important Points to Remember...............................................................................................................................187
Conguration Information..............................................................................................................................................188
Conguring a basic BGP network................................................................................................................................ 188
Enabling BGP............................................................................................................................................................ 188
Conguring a BGP peer........................................................................................................................................... 191
Conguring AS4 Number Representations........................................................................................................... 192
Conguring a BGP VRF address family................................................................................................................. 193
Route-refresh and Soft-reconguration................................................................................................................195
Aggregating Routes..................................................................................................................................................198
Filtering BGP Routes................................................................................................................................................198
Filtering BGP Routes Using Route Maps..............................................................................................................200
Filtering BGP Routes Using AS-PATH Information............................................................................................. 200
Conguring Peer Groups.........................................................................................................................................201
Conguring BGP Fast Fall-Over............................................................................................................................ 209
Conguring Passive Peering................................................................................................................................... 210
Maintaining Existing AS Numbers During an AS Migration..................................................................................211
Contents
7