Chapter 2
Catalyst 3550 Switch Cisco IOS Commands
mls qos dscp-mutation
Use the mls qos dscp-mutation interface configuration command to apply a Differentiated Services
Code Point (DSCP)-to-DSCP-mutation map to a DSCP-trusted port. Use the no form of this command
to return the DSCP-to-DSCP-mutation map to the default settings (no DSCP mutation).
Syntax Description
dscp-mutation-name
Defaults
The default DSCP-to-DSCP-mutation map is a null map, which maps incoming DSCPs to the same
DSCP values.
Command Modes
Interface configuration
Command History
Release
12.1(4)EA1
Usage Guidelines
You apply the DSCP-to-DSCP-mutation map to a port at the boundary of a quality of service (QoS)
administrative domain. If two QoS domains have different DSCP definitions between them, you use the
DSCP-to-DSCP-mutation map to translate a set of DSCP values to match the definition of another
domain. You apply the map only to ingress and to DSCP-trusted ports. Applying this map to a port
causes IP packets to be rewritten with newly mapped DSCP values at the ingress ports. If you apply the
DSCP mutation map to an untrusted port, to class of service (CoS) or IP-precedence trusted port, the
command has no immediate effect until the port becomes DSCP-trusted.
You can have multiple DSCP-to-DSCP-mutation maps and apply them to different Gigabit-capable
Ethernet ports. However, on 10/100 Ethernet ports, you can attach only one DSCP-to-DSCP-mutation
map to a group of twelve ports. For example, Fast Ethernet ports 0/1 to 0/12 are a group, Fast Ethernet
ports 0/13 to 0/24 are a group, Gigabit Ethernet port 0/1 is a group, and Gigabit Ethernet port 0/2 is a
group. When applying a mutation map to any port in a group, all ports in the same group are
automatically configured with the same map.
Examples
This example shows how to define the DSCP-to-DSCP-mutation map named dscpmutation1and to apply
the map to a port:
Switch(config)# mls qos map dscp-mutation dscpmutation1 10 11 12 13 to 30
Switch(config)# interface gigabitethernet0/1
Switch(config-if)# mls qos trust dscp
Switch(config-if)# mls qos dscp-mutation dscpmutation1
OL-8566-02
mls qos dscp-mutation dscp-mutation-name
no mls qos dscp-mutation dscp-mutation-name
Modification
This command was introduced.
Name of the DSCP-to-DSCP-mutation map, which was previously
defined with the mls qos map dscp-mutation global configuration
command.
Catalyst 3550 Multilayer Switch Command Reference
mls qos dscp-mutation
2-249