Using Differentiated Services Codepoint (DSCP) mapping
The DSCP Policy Table associates an 802.1p priority with a DSCP codepoint in an IPv4/IPv6 packet. Using DSCP codepoints in your network allows 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 following Default DSCP policy table. However, some codepoints, such as Assured Forwarding and Expedited Forwarding, have a default 802.1p priority setting.
Use the following commands to display the DSCP Policy table, configure the codepoint-priority assignments, and assign optional names to the codepoints.
Syntax:
show qos dscp-map
Displays the DSCP Policy table.
qos dscp-map codepoint priority0 - 7 [name ascii-string]
Configures an 802.1p priority for the specified codepoint and an optional (DSCP policy) name.
no qos dscp-map codepoint
Removes the currently configured 802.1p priority that is associated with the specified
codepoint and displays the
No-override setting. The codepoint policy name, if configured, is also removed.
no qos dscp-map codepointname
Deletes only the policy name, if configured, for the specified
codepoint.
|
DSCP Policy |
802.1p Priority |
DSCP Policy |
802.1p Priority |
DSCP Policy |
802.1p Priority |
|---|---|---|---|---|---|
|
000000 000001 000010 000011 000100 000101 000110 000111 001000 001001 001010 001011 001100 001101 001110 001111 010000 010001 010010 010011 010100 010101 |
No-override No-override No-override No-override No-override No-override No-override No-override No-override No-override 1No-override 11 No-override 21 No-override No-override No-override 01 No-override 01 No-override |
010110 010111 011000 011001 011010 011011 011100 011101 011110 011111 100000 100001 100010 100011 100100 100101 100110 100111 101000 101001 101010 |
31 No-override No-override No-override 41 No-override 41 No-override 51 No-override No-override No-override 61 No-override 61 No-override 71 No-override No-override No-override No-override |
101011 101100 101101 101110 101111 110000 110001 110010 110011 110100 110101 110110 110111 111000 111001 111010 111011 111100 111101 111110 111111 |
No-override No-override No-override 71No-override No-override No-override No-override No-override No-override No-override No-override No-override No-override No-override No-override No-override No-override No-override No-override No-override |
Expedited Forwarding codepoint configured by default.