ip as-path

Use ip as-path to configure an AS path list.

Use undo ip as-path to remove an AS path list.

Syntax

ip as-path as-path-number { deny | permit } regular-expression

undo ip as-path as-path-number [ regular-expression | deny | permit ]

Default

No AS path lists exist.

Views

System view

Predefined user roles

network-admin

Parameters

as-path-number: Specifies an AS path list number in the range of 1 to 256.

deny: Specifies the match mode for the AS path list as deny.

permit: Specifies the match mode for the AS path list as permit.

regular-expression: Specifies an AS path regular expression, a string of 1 to 63 characters.

Usage guidelines

BGP routing updates contain an AS_PATH attribute field that identifies the ASs through which the routes have passed. An AS path regular expression, for example, ^200.*100$, matches the AS_PATH attribute that starts with AS 200 and ends with AS 100. For more information about regular expressions, see Fundamentals Configuration Guide.

Examples

# Configure AS path list 1 to permit routes whose AS_PATH attribute starts with 10.

<Sysname> system-view
[Sysname] ip as-path 1 permit ^10

Related commands

apply as-path

display ip as-path

if-match as-path