Bgp Regex-Eval-Optz-Disable - Dell Z9500 Reference Manual

The clear ip bgp command is required for this command to take effect and to
keep the BGP database consistent. Execute the clear ip bgp command right
after executing this command.
Related clear ip bgp
Commands

bgp regex-eval-optz-disable

Disables the Regex Performance engine that optimizes complex regular expression with BGP.
Z9500
Syntax
bgp regex-eval-optz-disable
To re-enable optimization engine, use the no bgp regex-eval-optz-disable
command.
Defaults Enabled.
Command ROUTER BGP (conf-router_bgp)
Modes
Command
Version
History
9.2(1.0)
8.2.1.0
7.6.1.0
Usage
BGP uses regular expressions (regex) to filter route information. In particular, the
Information
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 show ip protocols
Commands
Border Gateway Protocol
Description
Introduced on the Z9500.
Introduced on the E-Series ExaScale.
Introduced
– views information on all enabled and active routing protocols.
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