CLI Guide

For this command to take effect and to keep the BGP database consistent, you
need the clear ip bgp command. Execute the clear ip bgp command right
after executing this command.
Related
Commands
capture bgp-pdu max-buffer-size
bgp regex-eval-optz-disable
Disables the Regex Performance engine that optimizes complex regular expression with BGP.
Syntax
bgp regex-eval-optz-disable
To re-enable optimization engine, use the no bgp regex-eval-optz-disable
command.
Defaults Enabled.
Command Modes ROUTER BGP (conf-router_bgp)
Supported Modes Full–Switch
Command History
Version Description
9.9(0.0) Introduced on the FN IOM.
9.2(0.0) Introduced on the MXL 10/40GbE Switch IO Module.
Usage Information
BGP uses regular expressions (regex) to filter route information. In particular, the
use of regular expressions to filter routes based on AS-PATHs and communities is
quite common. In a large scale configuration, filtering millions of routes based on
regular expressions can be quite CPU intensive, as a regular expression evaluation
involves generation and evaluation of complex finite state machines.
BGP policies, containing regular expressions to match as-path and communities,
tend to use a lot of CPU processing time, which in turn affects the BGP routing
convergence. Additionally, the show bgp commands, which are filtered through
regular expressions, use up CPU cycles particularly with large databases. The Regex
Engine Performance Enhancement feature optimizes the CPU usage by caching
and reusing regular expression evaluation results. This caching and reuse may be at
the expensive of RP1 processor memory.
Related
Commands
show ip protocols — views information on all routing protocols enabled and active.
bgp router-id
Assign a user-given ID to a BGP router.
Syntax
bgp router-id ip-address
To delete a user-assigned IP address, use the no bgp router-id command.
IPv6 Border Gateway Protocol (IPv6 BGP)
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