Configuring Ip Precedence Marking - Cisco Nexus 9000 Series Configuration Manual

Configuring Marking
DETAILED STEPS
Command or Action
Step 1
configure terminal
Example:
switch# configure terminal
switch(config)#
Step 2 policy-map [type qos] [match-first]
policy-map-name
Example:
switch(config)# policy-map policy1
switch(config-pmap-qos)#
Step 3 class [type qos] {class-name | class-default}
[insert-before before-class-name]
Example:
switch(config-pmap-qos)# class class1
switch(config-pmap-c-qos)#
Step 4 set dscp dscp-value
Example:
switch(config-pmap-c-qos)# set
dscp af31
This example shows how to display the policy-map configuration:
switch# show policy-map policy1

Configuring IP Precedence Marking

You can set the value of the IP precedence field in bits 0–2 of the IPv4 type of service (ToS) field of the IP
header.
The device rewrites the last 3 bits of the ToS field to 0 for packets that match this class.
Note
Table 31: Precedence Values
Value
0-7
critical
Purpose
Enters global configuration mode.
Creates or accesses the policy map named policy-map-name and then
enters policy-map mode. The policy-map name can contain alphabetic,
hyphen, or underscore characters, is case sensitive, and can be up to
40 characters.
Creates a reference to class-name and enters policy-map class
configuration mode. The class is added to the end of the policy map
unless insert-before is used to specify the class to insert before. Use
the class-default keyword to select all traffic that is not currently
matched by classes in the policy map.
Sets the DSCP value to dscp-value. Standard values are shown in the
previous Standard DSCP Values table.
When the QoS policy is applied on the VLAN configuration level, the
DSCP value derives the CoS value for bridged and routed traffic from
the 3 most significant DSCP bits.
Cisco Nexus 9000 Series NX-OS Quality of Service Configuration Guide, Release 7.x
Configuring IP Precedence Marking
List of Precedence Values
IP precedence value
Critical precedence (5)
75