Installation manual

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Cisco MWR 2941 Mobile Wireless Edge Router Release 3.5 Command Reference, Cisco IOS Release 15.1(3)MR
OL-26895-01
Chapter Cisco MWR 2941 Router Command Reference, Release 15.1(3)MR
match dscp
For example, if you wanted the DCSP values of 0, 1, 2, 3, 4, 5, 6, or 7 (note that only one of the IP DSCP
values must be a successful match criterion, not all of the specified DSCP values), enter the match dscp
0 1 2 3 4 5 6 7 command.
This command is used by the class map to identify a specific DSCP value marking on a packet. In this
context, dscp-value arguments are used as markings only and have no mathematical significance. For
instance, the dscp-value of 2 is not greater than 1. The value simply indicates that a packet marked with
the dscp-value of 2 is different than a packet marked with the dscp-value of 1. The treatment of these
marked packets is defined by the user through the setting of Quality of Service (QoS) policies in
policy-map class configuration mode.
Match Packets on DSCP Values
To match DSCP values for IPv6 packets only, the match protocol ipv6 command must also be used.
Without that command, the DSCP match defaults to match both IPv4 and IPv6 packets.
To match DSCP values for IPv4 packets only, use the ip keyword. Without the ip keyword the match
occurs on both IPv4 and IPv6 packets. Alternatively, the match protocol ip command may be used with
match dscp to classify only IPv4 packets.
After the DSCP bit is set, other QoS features can then operate on the bit settings.
The network can give priority (or some type of expedited handling) to marked traffic. Typically, you set
the precedence value at the edge of the network (or administrative domain); data is then queued
according to the precedence. Weighted fair queueing (WFQ) can speed up handling for high-precedence
traffic at congestion points.
Examples The following example shows how to set multiple match criteria. In this case, two IP DSCP value and
one AF value.
Router(config)# class-map map1
Router(config-cmap)# match dscp 1 2 af11
Related Commands Command Description
class-map Creates a class map to be used for matching packets to a specified class.
match protocol ip Matches DSCP values for packets.
policy-map Creates or modifies a policy map that can be attached to one or more
interfaces to specify a service policy.
service-policy Attaches a policy map to an input interface or VC, or an output interface or
VC, to be used as the service policy for that interface or VC.
set dscp Marks the DSCP value for packets within a traffic class.
show class-map Displays all class maps and their matching criteria.