Qinq Class Of Service Marking; Set Cos Command; Syntax Description; Set Cos Command History - Cisco 10000 Series Configuration Manual

Class of Service Marking

QinQ Class of Service Marking

For EXP-to-CoS mapping in QinQ configurations, the parallel express forwarding (PXF) engine marks
both the inner and outer CoS bits.
For CoS-to-EXP mapping in QinQ configurations, the PXF engine looks at the CoS bits in the outer
dot1q header to determine how to mark the EXP bits.

set cos Command

To set the Layer 2 class of service (CoS) value of an outgoing packet, use the set cos command in
policy-map class configuration mode. To remove a specific CoS value setting, use the no form of this
command. By default, this command is disabled.
set cos cos-value
no set cos cos-value

Syntax Description

cos-value

set cos Command History

Cisco IOS Release
Release 12.0(16)BX
Release 12.2(28)SB
Release 12.2(31)SB2
Release 12.2(33)SB

Usage Guidelines for the set cos Command

The set cos command allows switches and routers to interoperate. By configuring the router to match
packets based on the CoS value (using the match cos command) and to set CoS values, you can configure
Layer 2 to Layer 3 mapping. If a packet that needs to be marked to differentiate user-defined QoS
services is leaving a router and entering a switch, the router can set the CoS value of the packet because
the switch can process the Layer 2 header.
Use the set cos command only in service policies that are attached in the output direction of an interface;
packets entering an interface cannot be set with a CoS value. You can configure a CoS value on an
Ethernet interface that is configured for 802.1Q or on a virtual access interface that is using an 802.1Q
interface.
Cisco 10000 Series Router Quality of Service Configuration Guide
7-12
Is a specific IEEE 802.1Q CoS value from 0 to 7.
Description
This command was introduced on the PRE2 only.
This command was integrated in Cisco IOS Release 12.2(28)SB for the
PRE2.
This command was integrated in Cisco IOS Release 12.2(31)SB2 for the
PRE3.
This command was introduced on the PRE4.
Chapter 7 Marking Traffic
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