Users Guide
Usage Information
BGP uses regular expressions (regex) to lter route information. In particular, the use of regular expressions
to lter routes based on AS-PATHs and communities is quite common. In a large scale conguration, ltering
millions of routes based on regular expressions can be quite CPU intensive, as a regular expression evaluation
involves generation and evaluation of complex nite 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 aects the BGP routing convergence. Additionally, the show bgp
commands, which are ltered 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.
Parameters
ip-address Enter an IP address in dotted decimal format to reset only that BGP neighbor.
Defaults The router ID is the highest IP address of the Loopback interface or, if no Loopback interfaces are
congured, the highest IP address of a physical interface on the router.
Command Modes ROUTER BGP
Command History
This guide is platform-specic. For command information about other platforms, refer to the relevant Dell
Networking OS Command Line Reference Guide.
The following is a list of the Dell Networking OS version history for this command.
Version 8.3.19.0 Introduced on the S4820T.
Version 8.4.2.1 Introduced on the C-Series and S4810.
Version 8.2.1.0 Introduced on the E-Series ExaScale.
Version 7.4.1.0 Introduced on the E-Series TeraScale.
Usage Information Peering sessions are reset when you change the router ID of a BGP router.
IPv6 Border Gateway Protocol (IPv6 BGP)
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