Administrator Guide

Table Of Contents
BFD Packet Format....................................................................................................................................................113
BFD Sessions............................................................................................................................................................... 114
BFD Three-Way Handshake.....................................................................................................................................115
Session State Changes............................................................................................................................................. 116
Important Points to Remember.................................................................................................................................... 116
Configure BFD...................................................................................................................................................................116
Configure BFD for Physical Ports...........................................................................................................................117
Configure BFD for Static Routes........................................................................................................................... 120
Configure BFD for OSPF.......................................................................................................................................... 121
Configure BFD for OSPFv3..................................................................................................................................... 123
Configure BFD for IS-IS........................................................................................................................................... 125
Configure BFD for BGP............................................................................................................................................ 127
Configure BFD for VRRP......................................................................................................................................... 132
Configuring Protocol Liveness................................................................................................................................135
Troubleshooting BFD................................................................................................................................................ 135
Chapter 9: Border Gateway Protocol IPv4 (BGPv4)....................................................................137
Autonomous Systems (AS)........................................................................................................................................... 137
Sessions and Peers..........................................................................................................................................................139
Establish a Session.................................................................................................................................................... 139
Route Reflectors..............................................................................................................................................................140
BGP Attributes..................................................................................................................................................................141
Best Path Selection Criteria.....................................................................................................................................141
Weight.......................................................................................................................................................................... 143
Local Preference........................................................................................................................................................ 143
Multi-Exit Discriminators (MEDs).......................................................................................................................... 144
Origin.............................................................................................................................................................................145
AS Path........................................................................................................................................................................ 145
Next Hop......................................................................................................................................................................146
Multiprotocol BGP...........................................................................................................................................................146
Implement BGP with Dell Networking OS..................................................................................................................147
Advertise IGP Cost as MED for Redistributed Routes..................................................................................... 147
Ignore Router-ID for Some Best-Path Calculations.......................................................................................... 148
Four-Byte AS Numbers............................................................................................................................................ 148
AS4 Number Representation.................................................................................................................................. 148
AS Number Migration............................................................................................................................................... 150
BGP4 Management Information Base (MIB).......................................................................................................151
Important Points to Remember...............................................................................................................................151
Configuration Information..............................................................................................................................................152
BGP Configuration.......................................................................................................................................................... 152
Enabling BGP.............................................................................................................................................................. 153
Configuring AS4 Number Representations..........................................................................................................156
Configuring Peer Groups..........................................................................................................................................157
Configuring BGP Fast Fall-Over.............................................................................................................................159
Configuring Passive Peering.................................................................................................................................... 161
Maintaining Existing AS Numbers During an AS Migration.............................................................................. 161
Allowing an AS Number to Appear in its Own AS Path.................................................................................... 162
Enabling Graceful Restart........................................................................................................................................163
Enabling Neighbor Graceful Restart......................................................................................................................163
Filtering on an AS-Path Attribute.......................................................................................................................... 164
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