3Com MSR 50, MSR 30 manual Ip community-list, 1203

1203

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Parameters as-path-number: AS path ACL number, in the range of 1 to 256.

deny: Specifies the matching mode for the AS path ACL as deny.

permit: Specifies the matching mode for the AS path ACL as permit.

regular-expression: Regular expression of AS path, a string of 1 to 50 characters.

BGP routing information contains the AS path attribute field that identifies the autonomous systems through which routing information has passed. Used to compare with the AS path attribute, a regular expression is a formula comprised of characters, for example, ^200. *100$, which matches AS path attribute fields that start with AS200 and end with AS100.

The meanings of special characters used in regular expressions are shown below:

Character	Meaning
.	Matches any single character, including blank space.
*	Matches 0 or more patterns.
+	Matches 1 or more patterns.
^	Matches the beginning of an input string.
$	Matches the end of an input string.
_	Matches a comma, left brace, right brace, left parenthesis, right
	parenthesis, the beginning of an input string, the end of an input
	string, or a space.
[ range ]	Means the range of single-character patterns.
-	Separates the ending points of a range.

Description Use the ip as-pathcommand to create an AS path ACL.

Use the undo ip as-pathcommand to remove an AS path ACL.

No AS path ACL is created by default.

Examples # Create an AS path ACL numbered 1, permitting routing information whose AS_PATH starts with 10.

<Sysname> system-view

[Sysname] ip as-path 1 permit ^10

ip community-list

Syntax ip community-listbasic-comm-list-num { deny permit } [ community-number-list ] [ internet no-advertiseno-exportno-export-subconfed] *

undo ip community-listbasic-comm-list-num [ community-number-list ] [ internet no-advertiseno-exportno-export-subconfed] *