(config-cmap-generic) match layer4-payload

To define match criteria for Layer 4 payloads, use the match layer4-payload command in class map generic configuration mode. Use the no form of this command to remove the Layer 4 payload match criteria from the class map.

[line_number] match layer4-payload [offset number] regex expression

no [line_number] match layer4-payload [offset number] regex expression

Syntax Description

line_number

(Optional) Line number that allows you to edit or delete individual match commands.

•For the ACE module, enter an integer from 1 to 1024 as the line number.

•For the ACE appliance, enter an integer from 2 to 1024 as the line number.

You can enter no line_number to delete long match commands instead of entering the entire line. The line numbers do not indicate any priority for the match statements.

offset number

(Optional) Specifies an absolute offset in the data where the Layer 4 payload expression search string starts. The offset starts at the first byte of the TCP or UDP body. Enter an integer from 0 to 999. The default is 0.

regex expression

Specifies the Layer 4 payload expression that is contained within the TCP or UDP entity body. The range is from 1 to 255 alphanumeric characters. For a list of the supported characters that you can use in regular expression strings, see Table 2-9.


Command Modes

Class map generic configuration mode

Admin and user contexts

Command History

ACE Module Release
Modification
A2(1.0)

This command was introduced.

A2(2.1)

This command supports the "\xST" metacharacter.


ACE Appliance Release
Modification
A3(1.0)

This command was introduced.


Usage Guidelines

You cannot configure more than one match layer4-payload command in the same match-all class map.

Generic data parsing begins at Layer 4 with the TCP or UDP payload, which allows you the flexibility to match Layer 5 data (in the case of LDAP or DNS) or any Layer 7 header or payload (for example, HTTP).