Reference Guide

Version 8.3.19.0 Introduced on the S4820T.
Version 8.3.11.1 Introduced on the Z9000.
Version 8.3.7.0 Introduced on the S4810.
Version 7.8.1.0 Introduced on the S-Series.
Version 7.7.1.0 Introduced on the C-Series.
Version 7.2.1.0 Introduced.
Usage
Information
This command is a knob to disable BGP next-hop resolution using BGP learned 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
Commands
clear ip bgp — clears the ip bgp.
bgp regex-eval-optz-disable
Disables the Regex Performance engine that optimizes complex regular expression with BGP.
S4820T
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, refer to the
relevant FTOS Command Line Reference Guide .
The following is a list of the FTOS version history for this command.
Version 8.3.19.0 Introduced on the S4820T.
Version 8.3.11.1 Introduced on the Z9000.
Version 8.3.7.0 Introduced on the S4810.
Version 7.8.1.0 Introduced on the S-Series.
Version 7.7.1.0 Introduced on the C-Series.
Version 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.
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