Packet Marking Overview
You can use packet marking in input policy maps to set or modify the attributes for traffic belonging to a specific class. For example, you can change the CoS value in a class or set IP DSCP or IP precedence values for a specific type of traffic. These new values are then used to determine how the traffic should be treated.
Default Marking
When an ingress or egress interface adds VLAN tags or MPLS labels, it requires a default value for the class of service and EXP values that go into those tags and labels.
On the router, one ingress default QoS mapping profile and one egress default QoS mapping profile are created and configured per device during initialization.
Packet Marking
The packet marking feature, also called explicit marking, provides users with a means to differentiate packets based on the designated markings. The router supports ingress and egress packet marking.
Supported Packet Marking Operations
This table shows the supported packet marking operations.
Supported Mark Types |
Range |
Support for Unconditional Marking |
Support for Conditional Marking |
---|---|---|---|
set discard-class |
0-1 |
ingress |
No |
set dscp |
0-63 |
ingress |
No |
set mpls experimental topmost |
0-7 |
ingress |
No |
set precedence |
0-7 |
ingress |
No |
set qos-group |
0-7 |
ingress |
No |