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Conguration Task List for Route Maps................................................................................................................ 130
Creating a Route Map..............................................................................................................................................130
Congure Route Map Filters................................................................................................................................... 132
Conguring Match Routes...................................................................................................................................... 132
Conguring Set Conditions..................................................................................................................................... 134
Congure a Route Map for Route Redistribution.................................................................................................135
Congure a Route Map for Route Tagging........................................................................................................... 135
Continue Clause........................................................................................................................................................136
8 Bidirectional Forwarding Detection (BFD)...................................................................................................137
How BFD Works..............................................................................................................................................................137
BFD Packet Format........................................................................................................................................................138
BFD Sessions.................................................................................................................................................................. 139
BFD Three-Way Handshake.......................................................................................................................................... 140
Session State Changes..................................................................................................................................................142
Important Points to Remember.............................................................................................................................. 142
Congure BFD................................................................................................................................................................ 142
Congure BFD for Physical Ports...........................................................................................................................143
Congure BFD for Static Routes............................................................................................................................144
Congure BFD for OSPF......................................................................................................................................... 147
Congure BFD for OSPFv3......................................................................................................................................151
Congure BFD for IS-IS...........................................................................................................................................154
Congure BFD for BGP...........................................................................................................................................156
Conguring Protocol Liveness................................................................................................................................ 164
9 Border Gateway Protocol IPv4 (BGPv4).................................................................................................... 165
Autonomous Systems (AS)...........................................................................................................................................166
Sessions and Peers........................................................................................................................................................ 168
Establish a Session...................................................................................................................................................168
Route Reectors.............................................................................................................................................................169
Communities................................................................................................................................................................... 170
BGP Attributes................................................................................................................................................................170
Best Path Selection Criteria.................................................................................................................................... 170
Weight..............................................................................................................................................................................172
Local Preference............................................................................................................................................................. 172
Multi-Exit Discriminators (MEDs)...........................................................................................................................173
Origin................................................................................................................................................................................ 174
AS Path............................................................................................................................................................................ 174
Next Hop......................................................................................................................................................................... 175
Multiprotocol BGP..........................................................................................................................................................175
Implement BGP with Dell Networking OS...................................................................................................................175
Additional Path (Add-Path) Support......................................................................................................................175
Advertise IGP Cost as MED for Redistributed Routes........................................................................................ 176
Ignore Router-ID for Some Best-Path Calculations............................................................................................. 176
Four-Byte AS Numbers............................................................................................................................................176
AS4 Number Representation...................................................................................................................................177
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