Users Guide

IP Fragment Handling........................................................................................................................................................106
IP Fragments ACL Examples...................................................................................................................................... 106
Layer 4 ACL Rules Examples...................................................................................................................................... 106
Configure a Standard IP ACL........................................................................................................................................... 107
Configuring a Standard IP ACL Filter........................................................................................................................ 108
Configure an Extended IP ACL........................................................................................................................................ 109
Configuring Filters with a Sequence Number...........................................................................................................109
Configuring Filters Without a Sequence Number.....................................................................................................110
Configure Layer 2 and Layer 3 ACLs............................................................................................................................... 110
Assign an IP ACL to an Interface.......................................................................................................................................111
Applying an IP ACL.............................................................................................................................................................. 111
Counting ACL Hits........................................................................................................................................................ 112
Configure Ingress ACLs..................................................................................................................................................... 112
Configure Egress ACLs...................................................................................................................................................... 112
Applying Egress Layer 3 ACLs (Control-Plane)........................................................................................................ 113
IP Prefix Lists.......................................................................................................................................................................114
Configuration Task List for Prefix Lists......................................................................................................................114
ACL Resequencing..............................................................................................................................................................117
Resequencing an ACL or Prefix List...........................................................................................................................118
Route Maps......................................................................................................................................................................... 119
Logging of ACL Processes................................................................................................................................................ 119
Guidelines for Configuring ACL Logging................................................................................................................... 120
Configuring ACL Logging............................................................................................................................................ 120
Flow-Based Monitoring Support for ACLs...................................................................................................................... 121
Enabling Flow-Based Monitoring................................................................................................................................122
Chapter 9: Bidirectional Forwarding Detection (BFD)..................................................................... 124
How BFD Works.................................................................................................................................................................124
BFD Packet Format..................................................................................................................................................... 125
BFD Sessions................................................................................................................................................................ 126
BFD Three-Way Handshake....................................................................................................................................... 127
Session State Changes................................................................................................................................................128
Important Points to Remember........................................................................................................................................128
Configure BFD....................................................................................................................................................................128
Configure BFD for Physical Ports.............................................................................................................................. 129
Configure BFD for Static Routes................................................................................................................................131
Configure BFD for OSPF.............................................................................................................................................133
Configure BFD for OSPFv3........................................................................................................................................ 135
Configure BFD for IS-IS.............................................................................................................................................. 136
Configure BFD for BGP...............................................................................................................................................138
Configure BFD for VRRP............................................................................................................................................ 144
Configuring Protocol Liveness....................................................................................................................................147
Troubleshooting BFD................................................................................................................................................... 147
Chapter 10: Border Gateway Protocol IPv4 (BGPv4).......................................................................149
Autonomous Systems (AS).............................................................................................................................................. 149
Sessions and Peers.............................................................................................................................................................151
Establish a Session........................................................................................................................................................151
Route Reflectors................................................................................................................................................................152
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Contents