Concept Guide

Congure BFD for IS-IS............................................................................................................................................161
Congure BFD for BGP........................................................................................................................................... 163
Congure BFD for VRRP..........................................................................................................................................171
Conguring Protocol Liveness................................................................................................................................ 173
9 Border Gateway Protocol (BGP).................................................................................................................174
BGP IP version 4 (BGPv4) Overview.......................................................................................................................... 174
BGP Autonomous Systems...........................................................................................................................................175
AS4 Number Representation.................................................................................................................................. 176
Four-Byte AS Numbers............................................................................................................................................178
Multiprotocol BGP.......................................................................................................................................................... 178
Sessions and Peers.........................................................................................................................................................179
Establish a Session................................................................................................................................................... 179
BGP global and address family conguration..............................................................................................................180
BGP global conguration default values................................................................................................................180
BGP Attributes for selecting Best Path........................................................................................................................181
Best Path Selection Criteria.....................................................................................................................................181
Weight........................................................................................................................................................................183
Local Preference.......................................................................................................................................................183
Multi-Exit Discriminators (MEDs)...........................................................................................................................184
Origin..........................................................................................................................................................................185
AS Path......................................................................................................................................................................186
Next Hop................................................................................................................................................................... 186
Implement BGP with Dell EMC Networking OS......................................................................................................... 187
Additional Path (Add-Path) Support...................................................................................................................... 187
Advertise IGP Cost as MED for Redistributed Routes.........................................................................................187
Ignore Router-ID in Best-Path Calculation............................................................................................................ 188
AS Number Migration.............................................................................................................................................. 188
BGP4 Management Information Base (MIB)........................................................................................................189
Important Points to Remember.............................................................................................................................. 189
Conguration Information............................................................................................................................................. 190
Basic BGP conguration tasks..................................................................................................................................... 190
Enabling BGP............................................................................................................................................................ 190
Conguring a BGP peer...........................................................................................................................................193
Conguring AS4 Number Representations........................................................................................................... 194
Conguring a BGP VRF address family.................................................................................................................195
Route-refresh and Soft-reconguration................................................................................................................ 197
Aggregating Routes.................................................................................................................................................200
Filtering BGP Routes...............................................................................................................................................200
Filtering BGP Routes Using Route Maps..............................................................................................................200
Filtering BGP Routes Using AS-PATH Information.............................................................................................. 201
Conguring Peer Groups........................................................................................................................................ 202
Conguring BGP Fast Fall-Over.............................................................................................................................210
Conguring Passive Peering.................................................................................................................................... 211
Maintaining Existing AS Numbers During an AS Migration................................................................................. 212
Allowing an AS Number to Appear in its Own AS Path....................................................................................... 213
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