Advanced Traffic Management Guide K/KA/KB.15.15

4. Configure the switch to assign the DSCP policy to packets from the specified source-port.
Syntax:
interface port-list qos dscp codepoint
Assigns a DSCP policy to IP packets from the specified source-ports, and overwrites
the DSCP in these packets with the assigned codepoint value.
• A binary value for the six-bit codepoint from 000000 to 111111.
• A decimal value from 0 (low priority) to 63 (high priority) that corresponds to
a binary DSCP bit set
• An ASCII standard name for a binary DSCP bit set.
Enter ? to display the list of valid codepoint entries.
Syntax:
interface port-list qos dscp codepoint
The DSCP policy includes an 802.1p priority and determines the packet's queue
in the outbound port to which it is sent. If the packet leaves the switch on a tagged
port, it carries the 802.1p priority with it to the next downstream device.
Default: No-override
Syntax:
no interface [e] port-list qos
Removes a QoS classifier for the specified source-ports.
Syntax:
show qos source-port
Displays a listing of all source-port QoS classifiers currently in the running-config
file.
Example 157 Assigning DSCP policies (codepoint and associated 802.1p priority) to matching
packets
Assigning DSCP policies (codepoint and associated 802.1p priority) to matching packets with
the specified source-ports:
PriorityDSCPSource-Port
7000111A2
5000101B1-B3
1000010B4, C2
1. Determine if the DSCP codepoints that you want to use to mark matching packets already
have an 802.1p priority assigned, which could indicate use by existing applications
(show qos dscp-map command). This is not a problem as long as the configured
priorities are acceptable for all applications using the same DSCP.
Also, note that a DSCP must have an 802.1p priority configured before you can use it
to mark matching packets. If necessary, use the qos dscp-map codepoint priority
0 - 7 command to configure the DSCP policy (codepoint and associated 802.1p priority)
that you want to use to mark matching packets.
Figure 46 Viewing the current DSCP-priority mapping in the DSCP policy table
216 Quality of Service: Managing bandwidth effectively