Reference Guide

Border Gateway Protocol IPv4 (BGPv4) | 181
BGP Regular Expression Optimization
BGP policies that contain regular expressions to match against as-paths and communities might take a lot
of CPU processing time, and thus can affect BGP routing convergence. Also,
show bgp commands that
get filtered through regular expressions can take a lot of CPU cycles, especially when the database is large.
FTOS 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. This feature is turned on by
default. Use the command
bgp regex-eval-optz-disable in CONFIGURATION ROUTER BGP mode
to disable it if necessary.
Debugging BGP
Use any of the commands in EXEC Privilege mode to enable BGP debugging.
Command Syntax Command Mode Purpose
debug ip bgp [ip-address | peer-group
peer-group-name] [in | out]
EXEC Privilege View all information on BGP, including BGP
events, keepalives, notifications, and updates.
debug ip bgp dampening [in | out] EXEC Privilege View information on BGP route being
dampened.
debug ip bgp [ip-address | peer-group
peer-group-name] events [in | out]
EXEC Privilege View information on local BGP state changes
and other BGP events.
debug ip bgp [ip-address | peer-group
peer-group-name] keepalive [in | out]
EXEC Privilege View information about BGP KEEPALIVE
messages.
debug ip bgp [ip-address | peer-group
peer-group-name] notifications [in | out]
EXEC Privilege View information about BGP notifications
received from or sent to neighbors.
debug ip bgp [ip-address | peer-group
peer-group-name] updates [in | out]
[
prefix-list name]
EXEC Privilege View information about BGP updates and filter
by prefix name
debug ip bgp {ip-address |
peer-group-name} soft-reconfiguration
EXEC Privilege
Enable soft-reconfiguration debug.
Enable soft-reconfiguration debug.
To enhance debugging of soft
reconfig, use the following
command only when route-refresh
is not negotiated to avoid the peer
from resending messages:
bgp soft-reconfig-backup
In-BGP is shown via the show ip
protocols
command.