Users Guide
Conguring ACL Logging.......................................................................................................................................... 134
Flow-Based Monitoring Support for ACLs...................................................................................................................... 135
Behavior of Flow-Based Monitoring..........................................................................................................................135
Enabling Flow-Based Monitoring...............................................................................................................................136
9 Bidirectional Forwarding Detection (BFD)....................................................................138
How BFD Works............................................................................................................................................................. 138
BFD Packet Format.................................................................................................................................................. 139
BFD Sessions............................................................................................................................................................140
BFD Three-Way Handshake.......................................................................................................................................141
Session State Changes............................................................................................................................................. 143
Important Points to Remember.......................................................................................................................................143
Congure BFD................................................................................................................................................................ 143
Congure BFD for Physical Ports..............................................................................................................................144
Congure BFD for Static Routes...............................................................................................................................147
Congure BFD for OSPF.......................................................................................................................................... 148
Congure BFD for OSPFv3...................................................................................................................................... 150
Congure BFD for IS-IS............................................................................................................................................ 152
Congure BFD for BGP............................................................................................................................................ 154
Congure BFD for VRRP.......................................................................................................................................... 160
Conguring Protocol Liveness...................................................................................................................................163
Troubleshooting BFD.................................................................................................................................................163
10 Border Gateway Protocol IPv4 (BGPv4).................................................................... 165
Autonomous Systems (AS).............................................................................................................................................165
Sessions and Peers......................................................................................................................................................... 167
Establish a Session....................................................................................................................................................167
Route Reectors.............................................................................................................................................................168
BGP Attributes............................................................................................................................................................... 169
Best Path Selection Criteria......................................................................................................................................169
Weight....................................................................................................................................................................... 171
Local Preference........................................................................................................................................................171
Multi-Exit Discriminators (MEDs)..............................................................................................................................172
Origin........................................................................................................................................................................ 173
AS Path.....................................................................................................................................................................173
Next Hop...................................................................................................................................................................174
Multiprotocol BGP...........................................................................................................................................................174
Implement BGP with Dell Networking OS....................................................................................................................... 175
Additional Path (Add-Path) Support......................................................................................................................... 175
Advertise IGP Cost as MED for Redistributed Routes...............................................................................................175
Ignore Router-ID in Best-Path Calculation.................................................................................................................176
Four-Byte AS Numbers.............................................................................................................................................176
AS4 Number Representation.....................................................................................................................................176
AS Number Migration................................................................................................................................................178
BGP4 Management Information Base (MIB).............................................................................................................179
Important Points to Remember.................................................................................................................................179
7