Chapter 2
Cisco ME 3400 Ethernet Access Switch Cisco IOS Commands
priority
When you configure priority in an output policy map without the police command, you can only
configure the other queues for sharing by using the bandwidth remaining percent policy-map class
command. This command does not guarantee the allocated bandwidth, but the rate of distribution.
When you configure priority in an output policy map with the police command, you can configure other
queues for sharing by using the bandwidth policy-map class command and for shaping by using the
shape average policy-map class command.
You can associate the priority command only with a single unique class for all attached output policies
on the switch.
You cannot associate the priority command with the class-default of the output policy map.
You cannot configure priority and any other scheduling action (shape average or bandwidth) in the
same class.
The priority command uses a default queue limit for the class. You can change the queue limit by using
the queue-limit policy-map class command, overriding the default set by the priority command.
Examples
This example shows how to configure the class out-class1 as a strict priority queue so that all packets in
that class are sent before any other class of traffic. Other traffic queues are configured so that out-class-2
gets 50 percent of the remaining bandwidth and out-class3 gets 20 percent of the remaining bandwidth.
The class class-default receives the remaining 30 percent with no guarantees.
Switch(config)# policy-map policy1
Switch(config-pmap)# class out-class1
Switch(config-pmap-c)# priority
Switch(config-pmap-c)# exit
Switch(config-pmap)# class out-class2
Switch(config-pmap-c)# bandwidth remaining percent 50
Switch(config-pmap-c)# exit
Switch(config-pmap)# class out-class3
Switch(config-pmap-c)# bandwidth remaining percent 20
Switch(config-pmap-c)# exit
Switch(config-pmap)# exit
Switch(config)# interface fastethernet0/1
Switch(config-if)# service-policy output policy1
Switch(config-if)# exit
This example shows how to use the priority with police commands to configure out-class1 as the
priority queue, with traffic going to the queue limited to 20000000 bits per second (bps) so that the
priority queue never uses more than that. Traffic above that rate is dropped. The other traffic queues are
configured as in the previous example.
Switch(config)# policy-map policy1
Switch(config-pmap)# class out-class1
Switch(config-pmap-c)# priority
Switch(config-pmap-c)# police 20000000
Switch(config-pmap-c)# exit
Switch(config-pmap)# class out-class2
Switch(config-pmap-c)# bandwidth percent 50
Switch(config-pmap-c)# exit
Switch(config-pmap)# class out-class3
Switch(config-pmap-c)# bandwidth percent 20
Switch(config-pmap-c)# exit
Switch(config-pmap)# exit
Switch(config)# interface fastethernet0/1
Switch(config-if)# service-policy output policy1
Switch(config-if)# exit
You can verify your settings by entering the show policy-map privileged EXEC command.
Cisco ME 3400 Ethernet Access Switch Command Reference
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