Reference Guide

Access Control Lists (ACL) | 255
Example
Figure 6-15. Command Example: ip as-path access-list
Usage
Information
Use the match as-path or neighbor filter-list commands to apply the AS-PATH ACL to BGP
routes.
Command
History
Related
Commands
permit
e
Create a filter to forward BGP routes that match the route’s AS-PATH attributes. Use regular
expressions to identify which routes are affected by this filter.
Syntax
permit as-regular-expression
To remove this filter, use the no permit as-regular-expression command.
Parameters
Defaults
Not configured
Command Modes
AS-PATH ACL
FTOS(conf)#ip as-path access-list TestPath
FTOS(config-as-path)#
Version 8.1.1.0 Introduced on E-Series ExaScale
Version 7.8.1.0 Increased name string to accept up to 140 characters. Prior to 7.8.1.0, names are up to
16 characters long.
pre-Version 6.1.1.0 Introduced for E-Series
match as-path Match on routes contain a specific AS-PATH.
neighbor filter-list Configure filter based on AS-PATH information.
as-regular-expression
Enter a regular expression to match BGP AS-PATH attributes.
Use one or a combination of the following:
• . = (period) matches on any single character, including white space
• * = (asterisk) matches on sequences in a pattern (zero or more sequences)
• + = (plus sign) matches on sequences in a pattern (one or more sequences)
• ? = (question mark) matches sequences in a pattern (0 or 1 sequences). You
must enter an escape sequence (CNTL+v) prior to entering the ? regular
expression.
• [] = (brackets) matches a range of single-character patterns.
• ^ = (caret) matches the beginning of the input string. (If the caret is used at the
beginning of a sequence or range, it matches on everything BUT the characters
specified.)
• $ = (dollar sign) matches the end of the output string.
• _ = (underscore) matches a comma (,), left brace ({), right brace (}), left
parenthesis, right parenthesis, the beginning of the input string, the end of the
input string, or a space.
• | = (pipe) matches either character.