permit (bgp-as-path-list)

Creates and configures a permit as-path-list rule. The permit rule specifies a regular expression to match. This regular expression is matched against the BGP AS paths contained in routing updates. AS paths matching the provided string are filtered and a permit action is applied.

Supported in the following platforms:

  • Wireless Controllers — RFS 4000

  • Service Platforms — NX 95XX, NX 96XX


permit as-path <REG-EXP>


permit as-path <REG-EXP>
permit as-path <REG-EXP> Configures a match criteria (regular expression).
  • <REG-EXP> – Specify the regular expression to match (should not exceed 64 characters and should be unique to the AS path list rule)

Regular expressions are treated as a ‘ASCII string‘ and not as a sequence of numbers. Create a regular expression which is ideally suited to filter the required AS paths.

Usage Guidelines

The following table lists some of the characters used in forming regular expressions:
Click to expand in new window

Character to use Description
^ Indicates the start of a string
$ Indicates the end of a string
_ (underscore) Indicates a comma, left brace, right brace, start and end of an input string, or a space. For example, “_ _”.


nx9500-6C8809(config-bgp-as-path-list-test)#permit as-path _200_
nx9500-6C8809(config-bgp-as-path-list-test)#permit as-path _323_
nx9500-6C8809(config-bgp-as-path-list-test)#show context
bgp as-path-list test
 deny as-path ^100$
 permit as-path _323_
 permit as-path _200_

Related Commands

no (bgp-as-path-list) Removes the specified permit as-path ACL rule