Administrator Guide

Applying Egress ACLs................................................................................................................................................121
Applying Layer 3 Egress ACLs on Control-Plane Traffic.................................................................................. 121
Counting ACL Hits..................................................................................................................................................... 122
IP Prefix Lists....................................................................................................................................................................122
Configuration Task List for Prefix Lists................................................................................................................123
ACL Remarks.................................................................................................................................................................... 126
Configuring a Remark............................................................................................................................................... 126
Deleting a Remark......................................................................................................................................................126
ACL Resequencing...........................................................................................................................................................127
Resequencing an ACL or Prefix List...................................................................................................................... 127
Route Maps.......................................................................................................................................................................129
Important Points to Remember....................................................................................................................................129
Configuration Task List for Route Maps.............................................................................................................. 129
Configuring Match Routes....................................................................................................................................... 131
Configuring Set Conditions......................................................................................................................................132
Configure a Route Map for Route Redistribution.............................................................................................. 133
Configure a Route Map for Route Tagging......................................................................................................... 134
Continue Clause......................................................................................................................................................... 134
Configuring a UDF ACL.................................................................................................................................................. 134
Hot-Lock Behavior.......................................................................................................................................................... 136
Chapter 7: Bidirectional Forwarding Detection (BFD).................................................................137
How BFD Works............................................................................................................................................................... 137
BFD Packet Format...................................................................................................................................................138
BFD Sessions.............................................................................................................................................................. 139
BFD Three-Way Handshake.................................................................................................................................... 140
Session State Changes..............................................................................................................................................141
Important Points to Remember.....................................................................................................................................141
Configure BFD...................................................................................................................................................................141
Configure BFD for Physical Ports..........................................................................................................................142
Configure BFD for Static Routes........................................................................................................................... 143
Configure BFD for IPv6 Static Routes................................................................................................................. 146
Configure BFD for OSPF..........................................................................................................................................147
Configure BFD for OSPFv3.....................................................................................................................................152
Configure BFD for IS-IS........................................................................................................................................... 154
Configure BFD for BGP............................................................................................................................................156
Configure BFD for VRRP......................................................................................................................................... 162
Configuring Protocol Liveness................................................................................................................................164
Chapter 8: Border Gateway Protocol IPv4 (BGPv4)....................................................................165
Autonomous Systems (AS)........................................................................................................................................... 165
Sessions and Peers..........................................................................................................................................................167
Establish a Session.................................................................................................................................................... 167
Route Reflectors..............................................................................................................................................................168
BGP Attributes................................................................................................................................................................. 169
Best Path Selection Criteria....................................................................................................................................169
Weight........................................................................................................................................................................... 171
Local Preference.........................................................................................................................................................171
Multi-Exit Discriminators (MEDs).......................................................................................................................... 172
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