Reference Guide

address family ipv4 multicast
● Enable IPv4 multicast support on a BGP neighbor/peer group.
CONFIG-ROUTER-BGP-AF (Address Family) mode
neighbor [ip-address | peer-group-name] activate
BGP Regular Expression Optimization
The system optimizes processing time when using regular expressions by caching and re-using regular expression evaluated
results, at the expense of some memory in RP1 processor.
BGP policies that contain regular expressions to match against as-paths and communities might take a lot of CPU processing
time, thus affect BGP routing convergence. Also, show bgp commands that get filtered through regular expressions can to
take a lot of CPU cycles, especially when the database is large.
This feature is turned on by default. If necessary, use the bgp regex-eval-optz-disable command in CONFIGURATION
ROUTER BGP mode to disable it.
Debugging BGP
To enable BGP debugging, use any of the following commands.
● View all information about BGP, including BGP events, keepalives, notifications, and updates.
EXEC Privilege mode
debug ip bgp [ip-address | peer-group peer-group-name] [in | out]
● View information about BGP route being dampened.
EXEC Privilege mode
debug ip bgp dampening [in | out]
● View information about local BGP state changes and other BGP events.
EXEC Privilege mode
debug ip bgp [ip-address | peer-group peer-group-name] events [in | out]
● View information about BGP KEEPALIVE messages.
EXEC Privilege mode
debug ip bgp [ip-address | peer-group peer-group-name] keepalive [in | out]
● View information about BGP notifications received from or sent to neighbors.
EXEC Privilege mode
debug ip bgp [ip-address | peer-group peer-group-name] notifications [in | out]
● View information about BGP updates and filter by prefix name.
EXEC Privilege mode
debug ip bgp [ip-address | peer-group peer-group-name] updates [in | out] [prefix-list
name]
● Enable soft-reconfiguration debug.
EXEC Privilege mode
debug ip bgp {ip-address | peer-group-name} soft-reconfiguration
To enhance debugging of soft reconfig, use the bgp soft-reconfig-backup command only when route-refresh is not
negotiated to avoid the peer from resending messages.
In-BGP is shown using the show ip protocols command.
The system displays debug messages on the console. To view which debugging commands are enabled, use the show
debugging command in EXEC Privilege mode.
To disable a specific debug command, use the keyword no then the debug command. For example, to disable debugging of
BGP updates, use no debug ip bgp updates command.
To disable all BGP debugging, use the no debug ip bgp command.
To disable all debugging, use the undebug all command.
Border Gateway Protocol IPv4 (BGPv4)
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