Specifications

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Catalyst 4500 Series Switch Cisco IOS Command Reference—Release IOS XE 3.3.0XO(15.1(1)XO)
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Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches
set dscp
• Pr ece den ce
• Diff erentiated services c ode point (DSCP)
If you specify a “from-field” cat egory but do not specify the tabl e keyword and the applicable
table-map-name argument, the default action will be to copy the value associated with the “from-field”
category as the DSCP value. For instance, if you configure the set dscp cos command, the CoS value
will be copied and used as th e DSCP value.
Note The CoS field is a three-bit field, and the DSCP field is a six-bit field. If you configure the set dscp cos
command, only the three bits of the CoS field will be used.
If you configure t he set dscp qos-gr oup command, the QoS group value will be copied and used as the
DSCP value.
The valid value range for the DSCP is a number from 0 to 63. The valid value range for the QoS group
is a number from 0 to 63.
Set DSCP Values in IPv6 Environments
When this command is used in IPv6 environments, the default match occurs on both IP and IPv6 packets.
However, the actual packets set by this function are only those which meet the match criteria of the
class-map containing this function.
Set DSCP Values for IPv6 Packets Only
To set DSCP values for IPv6 values only, the match protocol ipv6 command must also be used. Without
that command, the DSCP match defaults to match both IPv4 and IPv6 packets.
Set DSCP Values for IPv4 Packets Only
To set DSCP values for IPv4 pa ckets only, use the ip keyword in the match command for classification.
Without the ip keyword, the match occurs on both IPv 4 and IPv6 packets.
Examples Packet-marking Values and Table Map
In the following example, the policy map called policy1 is created to use the packet-marking values
defined in a table map called table-map1. The table map was created earlier with the table-map (value
mapping) command. For more information about the tabl e-ma p (val ue mapping) command, se e the
table-map (value mapping) c ommand page.
This example shows how the DSCP value is set according to the CoS value defined in the table map
called table-map1.
Switch# configure terminal
Switch(config)# policy-map policy1
Switch(config-pmap)# class class-default
Switch(config-pmap-c)# set dscp cos table table-map1
Switch(config-pmap-c)# end
Switch#