Cisco Catalyst 3750 Metro Command Reference Manual page 404

random-detect
You cannot use the bandwidth, queue-limit, random-detect, and the shape policy-map class
configuration commands with the priority policy-map class configuration command in the same class
within the same policy map. However, you can use these commands in the same policy map.
If you use the dscp-based keyword, WRED uses the DSCP value to calculate the drop probability. If you
use the precedence-based keyword, WRED uses the IP precedence value to calculate the drop
probability. The dscp-based and precedence-based keywords are mutually exclusive. If you do not
specify either argument, WRED uses the IP precedence value to calculate the drop probability (the
default method).
You must enter the random-detect dscp-based command before specifying the values with the
random-detect dscp dscp min-threshold max-threshold mark-prob-denominator command. You must
enter the random-detect precedence-based command before specifying the values with the
random-detect precedence ip-precedence min-threshold max-threshold mark-prob-denominator
command.
To return to policy-map configuration mode, use the exit command. To return to privileged EXEC mode,
use the end command.
Examples This example shows how to configure the policy map called policy1 that contains a policy specification
for the class called class1. During times of congestion, IP precedence-based WRED packet drop is used
instead of tail drop.
Switch(config)# policy-map policy1
Switch(config-pmap)# class class1
Switch(config-pmap-c)# bandwidth 1000
Switch(config-pmap-c)# random-detect
This example shows how to enable DSCP-based WRED as a drop policy. It uses the DSCP value 8 for
class c1. The minimum threshold for DSCP value 8 is 24, the maximum threshold is 40, and the
mark-probability denominator is 512. The last command attaches the service policy to the port.
Switch(config)# class-map c1
Switch(config-cmap)# match ip dscp 8
Switch(config-cmap)# exit
Switch(config)# policy-map p1
Switch(config-pmap)# class c1
Switch(config-pmap-c)# bandwidth 48
Switch(config-pmap-c)# random-detect dscp-based
Switch(config-pmap-c)# random-detect dscp 8 24 40 512
Switch(config-pmap-c)# exit
Switch(config-pmap)# end
Switch(config)# interface gigabitethernet1/1/1
Switch(config-if)# service-policy output p1
You can verify your settings by entering the show policy-map privileged EXEC command.
Related Commands Command
bandwidth
class
policy-map
Catalyst 3750 Metro Switch Command Reference
2-376
Description
Specifies or modifies the minimum bandwidth provided to a class belonging
to a policy map attached to an ES port.
Specifies the name of the class whose traffic policy you want to create or
change.
Creates or modifies a policy map that can be attached to multiple ports to
specify a service policy.
Chapter 2 Catalyst 3750 Metro Switch Cisco IOS Commands
OL-9645-10