Continue Clause........................................................................................................................................................ 116
IP Fragment Handling..................................................................................................................................................... 116
IP Fragments ACL Examples................................................................................................................................... 116
Layer 4 ACL Rules Examples....................................................................................................................................117
Congure a Standard IP ACL.........................................................................................................................................117
Conguring a Standard IP ACL Filter......................................................................................................................118
Congure an Extended IP ACL......................................................................................................................................119
Conguring Filters with a Sequence Number........................................................................................................119
Conguring Filters Without a Sequence Number................................................................................................. 121
Congure Layer 2 and Layer 3 ACLs............................................................................................................................ 121
Assign an IP ACL to an Interface..................................................................................................................................122
Applying an IP ACL.........................................................................................................................................................122
Counting ACL Hits....................................................................................................................................................123
Congure Ingress ACLs................................................................................................................................................. 123
Congure Egress ACLs.................................................................................................................................................. 124
Applying Egress Layer 3 ACLs (Control-Plane).................................................................................................... 125
IP Prex Lists.................................................................................................................................................................. 125
Implementation Information.................................................................................................................................... 126
Conguration Task List for Prex Lists.................................................................................................................. 126
ACL Remarks.................................................................................................................................................................. 129
Conguring a Remark.............................................................................................................................................. 129
Deleting a Remark.................................................................................................................................................... 130
ACL Resequencing..........................................................................................................................................................131
Resequencing an ACL or Prex List........................................................................................................................131
Route Maps.....................................................................................................................................................................132
Implementation Information.................................................................................................................................... 132
Logging of ACL Processes............................................................................................................................................ 133
Guidelines for Conguring ACL Logging................................................................................................................134
Conguring ACL Logging.........................................................................................................................................134
Flow-Based Monitoring..................................................................................................................................................135
Behavior of Flow-Based Monitoring.......................................................................................................................135
Enabling Flow-Based Monitoring............................................................................................................................136
8 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............................................................................................................................145
Congure BFD for IPv6 Static Routes...................................................................................................................149
Congure BFD for OSPF..........................................................................................................................................151
Congure BFD for OSPFv3.....................................................................................................................................155
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