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Match tcp-flags, Match tcp-flags 6 – Allied Telesis AT-8100 Series User Manual

Page 1726

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Chapter 101: QoS Commands

1726

MATCH TCP-FLAGS

Syntax

match tcp-flags

ack|fin|rst|syn|urg

Parameters

ack

Indicates the Acknowledge TCP flag.

fin

Indicates the Finish TCP flag.

rst

Indicates the Reset TCP flag.

syn

Indicates the Synchronize TCP flag.

urg

Indicates the Urgent TCP flag.

Mode

Class Map mode

Description

Use this command to set a TCP flag as a matching criteria for a class
map. A TCP flag is a control bit. If a packet contains a TCP header, it
matches the criteria based on the FLAGS field within the header.

You can only add one TCP flag to a MATCH TCP-FLAGS command.
However, you can add multiple MATCH TCP-FLAGS commands to the
same class map, each containing a different TCP flag. Multiple commands
that apply to the same class map are filtered with an AND operand. For
example, the following command matches packets that contain the
Synchronize TCP flag:

match tcp-flags syn

In comparison, the following command matches packets that contain the
Acknowledge TCP flag:

match tcp-flags ack