Bgp Regular Expression Optimization; Retain Nh In Bgp Advertisement; Debugging Bgp - Dell Force10 C150 Configuration Manual

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, thus affect BGP routing convergence. Also,
through regular expressions can to 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
disable it if necessary.

Retain NH in BGP Advertisement

BGP does not update the NEXT_HOP attribute if it is a Route-Reflector.
configured to retain the NEXT_HOP attribute when advertising to internal BGP peer.

Debugging BGP

Use any of the commands in EXEC Privilege mode to enable BGP debugging.
Command Syntax
debug ip bgp [
ip-address
] [ in | out ]
peer-group-name
debug ip bgp dampening [ in | out ]
debug ip bgp [
ip-address
] events [ in | out ]
peer-group-name
debug ip bgp [
ip-address
] keepalive [ in | out ]
peer-group-name
debug ip bgp [
ip-address
] notifications [ in | out ]
peer-group-name
debug ip bgp [
ip-address
] updates [ in | out ]
peer-group-name
[ prefix-list name ]
bgp regex-eval-optz-disable
Command Mode
| peer-group
EXEC Privilege
EXEC Privilege
| peer-group
EXEC Privilege
| peer-group
EXEC Privilege
| peer-group
EXEC Privilege
| peer-group
EXEC Privilege
show bgp
in CONFIGURATION ROUTER BGP mode to
Purpose
View all information on BGP, including BGP
events, keepalives, notifications, and updates.
View information on BGP route being
dampened.
View information on local BGP state changes
and other BGP events.
View information about BGP KEEPALIVE
messages.
View information about BGP notifications
received from or sent to neighbors.
View information about BGP updates and filter
by prefix name
Border Gateway Protocol IPv4 (BGPv4) | 267
commands that get filtered
bgp retain-ibgp-nexthop
can be