Specifications

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Catalyst 4500 Se ries S wit ch C is co IO S C om mand R efer ence —Re lease I OS XE 3 .3.0 XO(1 5.1 (1)XO)
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Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches
set dscp
set dscp
To mark a packet by setting the differentiated services code point (DSCP) value in the type of service
(ToS) byte, use the set dscp command in policy-map class configuration mode. To remove a previously
set DSCP value, use the no form of this command.
set [ip] dscp {dscp-value | from-field [table ta ble-map-name]}
no set [ip] dscp {dscp-value | from-field [table table-map-name]
Syntax Description
Command Default Disabled
Command Modes Policy-map class configuration mode
Usage Guidelines Once the DSCP bit is set, other quality of service (QoS) features can then operate on the bit settings.
DSCP and Precedence V alues A re Mutuall y Exclusiv e
The set dscp command cannot be used w ith the set precedence command to mark the same packet. T he
two values, DSCP and precedence, are mutually exclusive. A packet can have one value or the other, but
not both.
You can use this command to specify the “from-field” packet-marking category to be used f or mapping
and setting the DSCP value. The “from-field” packet-marking categories are as follows:
• Class of service (CoS)
• QoS group
ip (Optional) Specifies that the match is for IPv4 packets only. If not used, the
match is on both IPv4 and IPv6 packets.
dscp-value A number from 0 to 63 that sets the DSCP value. A mnemonic name for
commonly used values can also be used.
from-field Specific packet-marking category to be used to set the DSCP value of the
packet. If you are using a table map for mapping and converting
packet-marking values, this esta blishes the “map from” pa cket-marking
category. Packet-marking category keywords are as follows:
• cos
• qos-group
• dscp
• precedence
table (Optional) Used in conjunction with the from-field argument. Indicates that
the values set in a specified table map will be used to set the DSCP value.
table-map-name (Optional) Used in conjunction with the table keyword. Name of the table
map used to specify the DSCP value. The name can be a maximum of 64
alphanu mer ic c ha rac ter s.