Cisco Systems 3130 Classifying, Policing, and Marking Traffic on Physical Ports by Using Policy Maps

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Cisco Catalyst Blade Switch 3130 for Dell Software Configuration Guide
OL-13270-01
Chapter36 Co nf iguring QoS
Configuring Standard QoS
Classifying, Policing, and Marking Traffic on Physical Ports by Using Policy Maps
You can configure a nonhierarchical policy map on a physical port that specifies which traffic class to
act on. Actions can include trusting the CoS, DSCP, or IP precedence values in the traffic class; setting
a specific DSCP or IP precedence value in the traffic class; and specifying the traffic bandwidth
limitations for each matched traffic class (policer) and the action to take when the traffic is out of prof ile
(marking).
A policy map also has these characteristics:
•A policy map can contain multiple class statements, each with different match criteria and policers.
•A separate policy-map class can exist for each type of traffic received through a port.
Follow these guidelines when configuring policy maps on physical ports:
•You can attach only one policy map per ingress port.
•If you configure the IP-precedence-to-DSCP map by using the mls qos map ip-prec-dscp
dscp1...dscp8 global configuration command, the settings only affect packets on ing ress i nte rface s
that are configured to trust the IP precedence value. In a policy map, if you set the packet IP
precedence value to a new value by using the set ip precedence new-precedence policy-map class
configuration command, the egress DSCP valu e is n ot affected by the IP-precedence-to-DSCP map.
If you want the egress DSCP value to be different than the ingress value, use the set dscp new-dscp
policy-map class configuration command.
•If you enter or have used the set ip dscp command, the switch changes this command to set dscp in
its configuration.
•You can use the set ip precedence or the set precedence policy-map class configuration command
to change the packet IP precedence value. This setting appears as set ip precedence in the switch
configuration.
•You can configure a separate second-level policy map for each class defined for the port. The
second-level policy map specifies the police action to take for each traffic class. For i nf o rm atio n o n
configuring a hierarchical policy map, see Classifying, Policing, and Marking Traffic on SVIs by
Using Hierarchical Policy Maps, page 36-52.