Users Guide

IP Fragments ACL Examples....................................................................................................................................113
Layer 4 ACL Rules Examples................................................................................................................................... 113
Congure a Standard IP ACL.........................................................................................................................................114
Conguring a Standard IP ACL Filter......................................................................................................................115
Congure an Extended IP ACL......................................................................................................................................116
Conguring Filters with a Sequence Number........................................................................................................116
Conguring Filters Without a Sequence Number..................................................................................................117
Congure Layer 2 and Layer 3 ACLs............................................................................................................................ 118
Assign an IP ACL to an Interface...................................................................................................................................118
Applying an IP ACL..........................................................................................................................................................119
Counting ACL Hits.................................................................................................................................................... 119
Congure Ingress ACLs................................................................................................................................................. 120
Congure Egress ACLs..................................................................................................................................................120
Applying Egress Layer 3 ACLs (Control-Plane)..................................................................................................... 121
IP Prex Lists.................................................................................................................................................................. 122
Implementation Information.................................................................................................................................... 122
Conguration Task List for Prex Lists.................................................................................................................. 122
ACL Resequencing......................................................................................................................................................... 126
Resequencing an ACL or Prex List.......................................................................................................................126
Route Maps..................................................................................................................................................................... 127
Implementation Information.................................................................................................................................... 128
Flow-Based Monitoring Support for ACLs.................................................................................................................. 128
Behavior of Flow-Based Monitoring.......................................................................................................................128
Enabling Flow-Based Monitoring............................................................................................................................129
7 Bidirectional Forwarding Detection (BFD)................................................................................................... 131
How BFD Works.............................................................................................................................................................. 131
BFD Packet Format..................................................................................................................................................132
BFD Sessions............................................................................................................................................................ 133
BFD Three-Way Handshake.................................................................................................................................... 134
Session State Changes............................................................................................................................................136
Important Points to Remember.................................................................................................................................... 136
Congure BFD................................................................................................................................................................ 136
Congure BFD for Physical Ports...........................................................................................................................137
Congure BFD for Static Routes............................................................................................................................140
Congure BFD for OSPF.........................................................................................................................................142
Congure BFD for OSPFv3.....................................................................................................................................147
Congure BFD for IS-IS...........................................................................................................................................149
Congure BFD for BGP............................................................................................................................................151
Congure BFD for VRRP.........................................................................................................................................158
Conguring Protocol Liveness.................................................................................................................................161
Troubleshooting BFD.................................................................................................................................................161
8 Border Gateway Protocol IPv4 (BGPv4).....................................................................................................163
Autonomous Systems (AS)........................................................................................................................................... 163
Sessions and Peers........................................................................................................................................................ 165
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