Users Guide
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)
Command History
This guide is platform-specific. For command information about other platforms, see the relevant Dell Networking
OS Command Line Reference Guide.
Version Description
9.8(1.0) Introduced on the Z9100–ON.
9.8(0.0P5) Introduced on the S4048-ON.
9.8(0.0P2) Introduced on the S3048-ON.
9.7(0.0) Introduced on the S6000–ON.
9.2(1.0) Introduced on the Z9500.
9.0.2.0 Introduced on the S6000.
8.3.19.0 Introduced on the S4820T.
8.3.11.1 Introduced on the Z9000.
8.3.7.0 Introduced on the S4810.
7.8.1.0 Introduced on the S-Series.
7.7.1.0 Introduced on the C-Series.
7.6.1.0 Introduced
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 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"
Router ID is 2.2.2.2
Area Routing for Networks
51 10.10.10.0/00
Routing Protocol is "bgp 1"
Cluster Id is set to 10.10.10.0
Border Gateway Protocol 357