Reference Guide

Implementation Information.......................................................................................................116
Flow-Based Monitoring Support for ACLs........................................................................................116
Behavior of Flow-Based Monitoring...........................................................................................116
Enabling Flow-Based Monitoring................................................................................................118
7 Bidirectional Forwarding Detection (BFD)......................................................121
How BFD Works.................................................................................................................................121
BFD Packet Format......................................................................................................................122
BFD Sessions................................................................................................................................124
BFD Three-Way Handshake........................................................................................................124
Session State Changes................................................................................................................ 125
Important Points to Remember........................................................................................................126
Configure BFD...................................................................................................................................126
Configure BFD for Physical Ports................................................................................................127
Configure BFD for Static Routes.................................................................................................130
Configure BFD for OSPF............................................................................................................. 132
Configure BFD for OSPFv3..........................................................................................................135
Configure BFD for IS-IS...............................................................................................................136
Configure BFD for BGP............................................................................................................... 139
Configure BFD for VRRP............................................................................................................. 146
Configuring Protocol Liveness................................................................................................... 149
Troubleshooting BFD..................................................................................................................149
8 Border Gateway Protocol IPv4 (BGPv4)..........................................................151
Autonomous Systems (AS)................................................................................................................ 151
Sessions and Peers............................................................................................................................ 153
Establish a Session.......................................................................................................................154
Route Reflectors................................................................................................................................154
BGP Attributes................................................................................................................................... 155
Best Path Selection Criteria.........................................................................................................156
Weight..........................................................................................................................................158
Local Preference......................................................................................................................... 158
Multi-Exit Discriminators (MEDs)................................................................................................ 159
Origin...........................................................................................................................................160
AS Path......................................................................................................................................... 161
Next Hop...................................................................................................................................... 161
Multiprotocol BGP.............................................................................................................................162
Implement BGP with Dell Networking OS....................................................................................... 162
Additional Path (Add-Path) Support........................................................................................... 162
Advertise IGP Cost as MED for Redistributed Routes................................................................ 162
Ignore Router-ID for Some Best-Path Calculations..................................................................163
Four-Byte AS Numbers............................................................................................................... 163