Using a global IP-Diffserv classifier to mark matching packets with an 802.1p priority
- Identify a DSCP used to set a policy in packets received from an upstream or edge switch.
- Determine the 802.1p priority (0 - 7) you want to apply to packets carrying the identified DSCP. (You can either maintain the priority assigned in the upstream or edge switch, or assign a new priority.)
-
If necessary, use the
qos dscp-map codepoint priority 0 - 7command to configure the DSCP policy (codepoint and associated 802.1p priority) that you want to use to mark matching packets. -
Enable IP-Diffserv mode by entering the
qos type-of-service diff-servicescommand.
Syntax:
qos type-of-service diff-services codepoint
Causes the switch to read the
codepoint
(DSCP) of an incoming IP packet and, when a match occurs, assign the associated 802.1p priority in the DSCP Policy table.
Options
no qos type-of-serviceDisables all ToS classifier operation.
no qos dscp-map codepointDisables direct 802.1p priority assignment to packets carrying the
codepoint, by reconfiguring the codepoint priority assignment in the DSCP table toNo-override. If this codepoint is in use as a DSCP policy for another Diffserv codepoint, you must disable or redirect the other Diffserv codepoint's DSCP policy before you can disable or change the codepoint. For example, in the first figure shown below, you cannot change the priority for the 000000 codepoint until you redirect the DSCP policy for 000001 from using 000000 as a policy.show qos type-of-serviceDisplays the current Type-of-Service configuration. In IP-Diffserv mode, it also shows the current direct 802.1p assignments and the current DSCP assignments covered later in this section.
Examples
show qos type-of-service
000110, and then enable diff-services:
