KB.15.15

Examples

Example 149 show qos type-of-service

An edge switch A in an untagged VLAN assigns a DSCP of 000110 on IP packets it receives on

port A6, and handles the packets with high priority (7). When these packets reach interior switch

B you want the switch to handle them with the same high priority. To enable this operation you

would configure an 802.1p priority of 7 for packets received with a DSCP of 000110, and then

enable diff-services:

Figure 37 Viewing the codepoints available for 802.1p priority assignments

Figure 38 Type-of-Service configuration that enables both 802.1p priority and DSCP policy

assignment

Assigning a DSCP policy for a global IP-Diffserv classifier

The preceding section describes how to forward an 802.1p priority level set by an edge (or

upstream) switch. This section describes how to use a global IP-Diffserv classifier to mark matching

packets with a new DSCP policy. A DSCP policy consists of a DSCP codepoint and an associated

802.1p priority.

You can use a global IP-Diffserv classifier to mark a DSCP policy at the same time with a global

IP-Diffserv classifier that marks an 802.1p priority if different DSCP codepoints are configured with

each classifier.

To use a global IP-Diffserv classifier to mark matching packets with a new DSCP policy, follow

these steps:

1. Identify the DSCP used to set a policy in packets received from an upstream or edge switch.

2. Create a new policy by using the qos dscp-map code-point priority 0 - 7

command to configure an 802.1p priority for the codepoint you will use to overwrite the DSCP

that the packet carries from upstream.

Assigning a DSCP policy for a global IP-Diffserv classifier 205