Differentiated Services Codepoint (DSCP) mapping

A codepoint must have an 802.1p priority assignment (0 - 7) before you can configure a policy for prioritizing packets. If a codepoint you want to use shows No-override in the Priority column of the DSCP map (show qos dscp-map), then you must assign a 0 - 7 priority before proceeding (qos dscp-map priority command).

The DSCP Policy Table associates an 802.1p priority with a specific ToS byte codepoint in an IPv4 packet. This enables you to set a LAN policy that operates independently of 802.1Q VLAN-tagging.

In the default state, most of the 64 codepoints do not assign an 802.1p priority, as indicated by No-override in the table below.

You can use the following command to list the current DSCP Policy table.

Syntax:


show qos dscp-map

Displays the DSCP Policy Table.

Partial display from the default DSCP Policy Table

DSCP codepoint

DSCP value

802.1p tag

DSCP policy name

000000

0

 

cs0

000001

1

No-override

 

000010

2

No-override

 

000011

3

No-override

 

000100

4

No-override

 

000101

5

No-override

 

000110

6

No-override

 

000111

7

No-override

 

001000

8

1

cs1

001001

9

No-override

 

001010

10

No-override

af11

001011

11

No-override