Bgp Regex-Eval-Optz-Disable - Dell MXL 10GbE Reference Manual

Command
Version 9.2(0.0)
History
Usage
This command is a knob to disable BGP next-hop resolution using BGP learned
Information
routes. During the next-hop resolution, only the first route that the next-hop
resolves through is verified for the route's protocol source and is checked if the
route is learned from BGP or not.
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.
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 9.2(0.0)
History
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
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 much 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.
Examples
Dell(conf-router_bgp)#no bgp regex-eval-optz-disable
Dell(conf-router_bgp)#do show ip protocols
Routing Protocol is "ospf 22222"
Border Gateway Protocol IPv4 (BGPv4)
Introduced on the MXL 10/40GbE Switch IO Module.
— clears the ip bgp.
Introduced on the MXL 10/40GbE Switch IO Module.
Router ID is 2.2.2.2
325