Reference Guide

Access Control Lists (ACL) | 271
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
Parameters
Defaults
Not configured
Command Modes
AS-PATH ACL
Command
History
show config
e
Display the current configuration.
Syntax
show config
Version 8.3.7.0 Introduced on S4810
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.
Version 8.1.1.0 Introduced on E-Series ExaScale
pre-Version 6.1.1.0 Introduced for E-Series