Users Guide

Guidelines for Configuring ACL Logging.................................................................................................................... 113
Configuring ACL Logging.............................................................................................................................................113
Flow-Based Monitoring Support for ACLs...................................................................................................................... 114
Enabling Flow-Based Monitoring................................................................................................................................ 115
Configuring UDF ACL.........................................................................................................................................................116
Chapter 8: Bidirectional Forwarding Detection (BFD)......................................................................119
How BFD Works................................................................................................................................................................. 119
BFD Packet Format..................................................................................................................................................... 120
BFD Sessions.................................................................................................................................................................121
BFD Three-Way Handshake....................................................................................................................................... 122
Session State Changes................................................................................................................................................123
Important Points to Remember........................................................................................................................................123
Configure BFD....................................................................................................................................................................123
Configure BFD for Physical Ports.............................................................................................................................. 124
Configure BFD for Static Routes............................................................................................................................... 126
Configure BFD for OSPF.............................................................................................................................................128
Configure BFD for OSPFv3........................................................................................................................................ 130
Configure BFD for IS-IS............................................................................................................................................... 131
Configure BFD for BGP...............................................................................................................................................133
Configure BFD for VRRP............................................................................................................................................ 139
Configuring Protocol Liveness....................................................................................................................................142
Troubleshooting BFD................................................................................................................................................... 142
Chapter 9: Border Gateway Protocol IPv4 (BGPv4)........................................................................ 144
Autonomous Systems (AS).............................................................................................................................................. 144
Sessions and Peers............................................................................................................................................................146
Establish a Session.......................................................................................................................................................146
Route Reflectors................................................................................................................................................................ 147
BGP Attributes................................................................................................................................................................... 148
Best Path Selection Criteria........................................................................................................................................148
Weight........................................................................................................................................................................... 150
Local Preference..........................................................................................................................................................150
Multi-Exit Discriminators (MEDs)...............................................................................................................................151
Origin..............................................................................................................................................................................152
AS Path......................................................................................................................................................................... 152
Next Hop.......................................................................................................................................................................153
Multiprotocol BGP............................................................................................................................................................. 153
Implement BGP with Dell Networking OS...................................................................................................................... 153
Advertise IGP Cost as MED for Redistributed Routes............................................................................................154
Ignore Router-ID in Best-Path Calculation............................................................................................................... 154
Four-Byte AS Numbers...............................................................................................................................................154
AS4 Number Representation......................................................................................................................................155
AS Number Migration..................................................................................................................................................156
BGP4 Management Information Base (MIB)........................................................................................................... 157
Important Points to Remember..................................................................................................................................158
Configuration Information.................................................................................................................................................158
BGP Configuration.............................................................................................................................................................159
Enabling BGP................................................................................................................................................................159
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Contents