Reference Guide

Border Gateway Protocol IPv4 (BGPv4) | 223

• If the corresponding capability is received in the peer’s Open message, BGP will mark the peer as

supporting the AFI/SAFI.

• When exchanging updates with the peer, BGP sends and receives IPv4 Multicast routes if the peer is

marked as supporting that AFI/SAFI.

• Exchange of IPv4 Multicast route information occurs through the use of two new attributes called

MP_REACH_NLRI and MP_UNREACH_NLRI, for feasible and withdrawn routes, respectively.

• If the peer has not been activated in any AFI/SAFI, the peer remains in Idle state.

Most FTOS BGP IPv4 Unicast commands are extended to support the IPv4 Multicast RIB using extra

options to the command. Refer to the FTOS Command Line Interface Reference for a detailed description

of the MBGP commands.

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,

show bgp commands that get filtered

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

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