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.
A partial display of the default DSCP Policy Table is show 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.
DSCP CodePoint |
DSCP Value |
802.1p tag |
DSCP Policy name |
|---|---|---|---|
000000 |
0 |
0 |
cs0 |
000001 |
1 |
0 |
|
000010 |
2 |
0 |
|
000011 |
3 |
0 |
|
000100 |
4 |
0 |
|
000101 |
5 |
0 |
|
000110 |
6 |
0 |
|
000111 |
7 |
0 |
|
001000 |
8 |
1 |
cs1 |
001001 |
9 |
1 |
|
001010 |
10 |
1 |
af11 |
001011 |
11 |
1 |
|
001100 |
12 |
1 |
af12 |
001101 |
13 |
1 |
|
001110 |
14 |
1 |
af13 |
001111 |
15 |
1 |
|
010000 |
16 |
2 |
cs2 |
010001 |
17 |
2 |
|
010010 |
18 |
2 |
af21 |
010011 |
19 |
2 |