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S e n d f e e d b a c k t o n x 5 0 0 0 - d o c f e e d b a c k @ c i s c o . c o m
1-10
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
OL-16597-01
Chapter 1 Configuring QoS
Configuring System Classes
To configure a class map for a system class, perform this task:
Configuring Policy Maps
The
policy-map
command is used to create a named object representing a set of policies that are to be
applied to a set of traffic classes.
The switch provides two default system classes: a no-drop class for lossless service and a drop class for
best-effort service. You can define up to four additional system classes for Ethernet traffic.
You need to create a policy map to specify the policies for any user-defined class. In the policy-map, you
can configure the QoS parameters for each class. You can use the same policy map to modify the
configuration of the default classes.
Note
Before creating the policy map, define a class map for each new system class.
To configure a policy map, perform this task:
Command
Purpose
Step 1
switch#
configure terminal
Enters configuration mode.
Step 2
switch(config)#
class-map
name
Creates a named object that represents a class of
traffic. Class map names can contain alphabetic,
hyphen, or underscore characters, are case sensitive,
and can be up to 40 characters.
Step 3
switch(config-cmap)#
match cos
cos-value
Specifies the CoS value to match for classifying
packets into this class. You can configure a CoS value
in the range of 1 to 7.
Note
CoS value 0 is reserved for the default drop
system class (
class-default
).
Command
Purpose
Step 1
switch#
configure terminal
Enters configuration mode.
Step 2
switch(config)#
policy-map
name
Creates a named object representing a set of policies
that are to be applied to a set of traffic classes.
Policy-map names can contain alphabetic, hyphen, or
underscore characters, are case sensitive, and can be up
to 40 characters.
Step 3
switch(config-pmap)#
class
class-name
Associates a class map with the policy map, and enters
configuration mode for the specified system class.
Step 4
switch(config-pmap-c)#
pause
no-drop
(Optional) Configures a no-drop class. If you do not
specify this subcommand, the default policy is drop.
Note
The operation for drop policy is simple tail
drop, where arriving packets will be dropped if
the queue increases to its allocated size