Cisco Nexus 5000 Series Switch CLI Software Configuration Guide, NX-OS 4.0(1a)N1 (OL-16597-01, January 2009)

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Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
OL-16597-01
Chapter 31 Configuring QoS
Configuring System Classes
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:
Note The switch distributes all the policy map configuration values to the attached network adapters.
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
Step 5
switch(config-pmap-c)# mtu value
(Optional) Specifies the MTU value in bytes.
Step 6
switch(config-pmap-c) bandwidth percent
percentage
(Optional) Specifies the guaranteed percentage of
interface bandwidth allocated to this class. This
parameter applies to all Ethernet interfaces that do not
have ingress or egress policies configured.
Step 7
switch(config-pmap-c) priority
(Optional) Specifies that traffic in this class is mapped
to a strict priority queue. This parameter applies to all
Ethernet interfaces that do not have ingress or egress
policies configured.
Step 8
switch(config-pmap-c) multicast-optimize
(Optional) Enables multicast optimization. Multicast
traffic in this class will be served by all available
multicast queues.
Note Only one class in a policy map can be
configured for multicast optimization.