Administrator Guide

Configure Ingress ACLs..................................................................................................................................................... 115
Configure Egress ACLs......................................................................................................................................................116
Applying Egress Layer 3 ACLs (Control-Plane)........................................................................................................ 117
IP Prefix Lists.......................................................................................................................................................................117
Configuration Task List for Prefix Lists......................................................................................................................118
ACL Remarks.......................................................................................................................................................................121
Configuring a Remark...................................................................................................................................................121
Deleting a Remark.........................................................................................................................................................121
ACL Resequencing.............................................................................................................................................................122
Resequencing an ACL or Prefix List.......................................................................................................................... 122
Route Maps........................................................................................................................................................................ 123
Logging of ACL Processes................................................................................................................................................124
Guidelines for Configuring ACL Logging................................................................................................................... 124
Configuring ACL Logging............................................................................................................................................ 125
Flow-Based Monitoring.....................................................................................................................................................125
Enabling Flow-Based Monitoring................................................................................................................................127
Configuring UDF ACL........................................................................................................................................................ 127
Configuring IP Mirror Access Group................................................................................................................................130
Sample Configuration.................................................................................................................................................. 130
Example of viewing IP mirror–access–group applied to an Interface...................................................................130
8 Bidirectional Forwarding Detection (BFD)................................................................................... 132
How BFD Works.................................................................................................................................................................132
BFD Packet Format..................................................................................................................................................... 133
BFD Sessions................................................................................................................................................................ 134
BFD Three-Way Handshake....................................................................................................................................... 135
Session State Changes................................................................................................................................................136
Important Points to Remember....................................................................................................................................... 136
Configure BFD....................................................................................................................................................................136
Configure BFD for Physical Ports.............................................................................................................................. 137
Configure BFD for Static Routes............................................................................................................................... 138
Configure BFD for IPv6 Static Routes.......................................................................................................................141
Configure BFD for OSPF.............................................................................................................................................143
Configure BFD for OSPFv3........................................................................................................................................ 148
Configure BFD for IS-IS.............................................................................................................................................. 150
Configure BFD for BGP...............................................................................................................................................152
Configure BFD for VRRP............................................................................................................................................ 159
Configuring Protocol Liveness.................................................................................................................................... 161
9 Border Gateway Protocol (BGP).................................................................................................162
BGP IP version 4 (BGPv4) Overview..............................................................................................................................162
BGP Autonomous Systems.........................................................................................................................................162
AS4 Number Representation......................................................................................................................................164
Four-Byte AS Numbers...............................................................................................................................................166
BGP router ID............................................................................................................................................................... 166
Sessions and Peers...................................................................................................................................................... 166
Establish a Session.......................................................................................................................................................166
BGP Attributes for selecting Best Path.................................................................................................................... 167
Multiprotocol BGP........................................................................................................................................................172
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