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Command Reference Guide

ManualsBrandsDell ManualsserversDell Force10 S4810P
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776 | IPv6 Border Gateway Protocol (IPv6 BGP)
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Command Modes
ROUTER BGP (conf-router_bgp)
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
Command
History
bgp router-id
c e
Assign a user-given ID to a BGP router.
Syntax
bgp router-id ip-address
To delete a user-assigned IP address, enter no bgp router-id.
Parameters
Defaults
The router ID is the highest IP address of the Loopback interface or, if no Loopback
interfaces are configured, the highest IP address of a physical interface on the router.
Command Modes
ROUTER BGP
Command
History
Usage
Information
Peering sessions are reset when you change the router ID of a BGP router.
show ip protocols View information on all routing protocols enabled and active on the
E-Series.
Version 8.4.2.1 Introduced on C-Series and S4810.
Version 8.2.1.0 Introduced on E-Series ExaScale
Version 7.4.1.0 Introduced on E-Series TeraScale
ip-address
Enter an IP address in dotted decimal format to reset only that BGP neighbor.
Version 8.4.2.1 Introduced on C-Series and S4810
Version 8.2.1.0 Introduced on E-Series ExaScale
Version 7.4.1.0 Introduced on E-Series TeraScale