Table Of Contents

Configuring Marking

Information About Marking

Licensing Requirements for Marking

Prerequisites for Marking

Guidelines and Limitations

Configuring Marking

Configuring DSCP Marking

Configuring IP Precedence Marking

Configuring CoS Marking

Configuring QoS Group Marking

Configuring Discard Class Marking

Configuring Ingress and Egress Marking

Configuring DSCP Port Marking

Configuring Table Maps for Use in Marking

Configuring Marking Using Table Maps

Verifying the Marking Configuration

Example Configuration

Feature History for Marking

Configuring Marking

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This chapter describes how to configure the marking features that you can use to define the class of traffic to which the packet belongs to.

This chapter includes the following sections:

•Information About Marking

•Licensing Requirements for Marking

•Prerequisites for Marking

•Guidelines and Limitations

•Configuring Marking

•Verifying the Marking Configuration

•Example Configuration

•Feature History for Marking

Information About Marking

Marking is a method that you use to modify the QoS fields of the incoming and outgoing packets. The QoS fields that you can mark are CoS in Layer 2, and IP precedence and DSCP in Layer 3. QoS group and discard class are two labels local to the system that you can assign intermediate marking values, which you can then use to determine the final values marked in a packet.

You can use marking commands in traffic classes that are referenced in a policy map. The marking features that you can configure are listed in Table 4-1.

Table 4-1 Configurable Marking Features 

Marking Feature	Description
DSCP	Layer 3 Differentiated Service Code Point (DSCP). Note If you manipulate this dscp value, you cannot manipulate discard class values, and vice-versa.
IP precedence	Layer 3 IP precedence. Note IP precedence uses only the lower 3 bits of the Type of Service (TOS) field. The device overwrites the first 3 bits of the TOS field to 0.
CoS	Layer 2 Class of Service (CoS).
QoS group	Locally significant QoS values that can be manipulated and matched within the system. The range is from 0 to 126.
Discard class	Locally significant values that can be matched and manipulated within the system. The range is from 0 to 63. Note If you manipulate this discard class value, you cannot manipulate dscp values, and vice-versa.
Ingress and egress ports	Status of the marking applies to incoming or outgoing packets.
Using table maps	Method to use table maps for marking.

Unless noted as a restriction, you can apply marking features to both incoming and outgoing packets.

Licensing Requirements for Marking

The following table shows the licensing requirements for this feature:

Product	License Requirement
NX-OS	QoS requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation of the NX-OS licensing scheme, see the Cisco Nexus 7000 Series NX-OS Licensing Guide, Release 4.0.

However, using VDCs requires an Advanced Services license.

Prerequisites for Marking

Marking has the following prerequisites:

•You must be familiar with Chapter 2, "Using Modular QoS CLI."

•You are logged on to the switch.

•You are in the correct virtual device context (VDC). A VDC is a logical representation of a set of system resources. You can use the switchto vdc command with a VDC number.

Guidelines and Limitations

Use the following guidelines to configure marking:

•The set cos command is applicable only to 802.1Q interfaces, and you can only use it in egress policies.

•You can only use the set qos-group command in ingress policies.

•You can only use the set discard-class command in ingress policies.

Configuring Marking

You can combine one or more of the marking features in a policy map to control the setting of QoS values. You can then apply policies to either incoming or outgoing packets on an interface.

This section includes the following topics:

•Configuring DSCP Marking

•Configuring IP Precedence Marking

•Configuring CoS Marking

•Configuring QoS Group Marking

•Configuring Discard Class Marking

•Configuring Ingress and Egress Marking

•Configuring DSCP Port Marking

•Configuring Table Maps for Use in Marking

•Configuring Marking Using Table Maps

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Note Do not press Enter after you use the set command and before you add the rest of the command. If you press Enter directly after entering the set keyword, you will be unable to continue to configure with the QoS configuration.

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Configuring DSCP Marking

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Note If you configure this value, you cannot configure the discard-class value (see the "Configuring Discard Class Marking" section).

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You can set the DSCP value in the six most significant bits of the DiffServ field of the IP header to a specified value. You can enter numeric values from 0 to 60, as well as the standard DSCP values shown in Table 4-2.

Table 4-2 Standard DSCP Values 

Value	List of DSCP Values
af11	AF11 dscp (001010)—decimal value 10
af12	AF12 dscp (001100)—decimal value 12
af13	AF13 dscp (001110)—decimal value 14
af21	AF21 dscp (010010)—decimal value 18
af22	AF22 dscp (010100)—decimal value 20
af23	AF23 dscp (010110)—decimal value 22
af31	AF31 dscp (011010)—decimal value 26
af32	AF40 dscp (011100)—decimal value 28
af33	AF33 dscp (011110)—decimal value 30
af41	AF41 dscp (100010)—decimal value 34
af42	AF42 dscp (100100)—decimal value 36
af43	AF43 dscp (100110)—decimal value 38
cs1	CS1 (precedence 1) dscp (001000)—decimal value 8
cs2	CS2 (precedence 2) dscp (010000)—decimal value 16
cs3	CS3 (precedence 3) dscp (011000)—decimal value 24
cs4	CS4 (precedence 4) dscp (100000)—decimal value 32
cs5	CS5 (precedence 5) dscp (101000)—decimal value 40
cs6	CS6 (precedence 6) dscp (110000)—decimal value 48
cs7	CS7 (precedence 7) dscp (111000)—decimal value 56
default	Default dscp (000000)—decimal value 0
ef	EF dscp (101110)—decimal value 46

For more information about DSCP, see RFC 2475.

SUMMARY STEPS

1. config t

2. policy-map [type qos] [match-first] policy-map-name

3. class [type qos] {class-map-name | class-default} [insert-before before-class-map-name]

4. set dscp dscp-value

DETAILED STEPS

	Command	Purpose
Step 1	config t Example: switch# config t switch(config)#	Enters configuration mode.
Step 2	policy-map [type qos] [match-first] policy-map-name Example: switch(config)# policy-map policy1 switch(config-pmap-qos)#	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.
Step 3	class [type qos] {class-map-name | class-default} [insert-before before-class-map-name] Example: switch(config-pmap)# class class1 switch(config-pmap-c-qos)#	Creates a reference to class-map-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. Specify class-default to select all traffic not currently matched by classes in the policy map.
Step 4	set dscp dscp-value Example: switch(config-pmap-c-qos)# set dscp af31 switch(config-pmap-c-qos)#	Sets the DSCP value to dscp-value. Standard values are shown in Table 4-2.

Use the show policy-map command 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.

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Note The device rewrites the last 3 bits of the ToS field to 0 for packets that match this class.

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Table 4-3 shows the precedence values.

Table 4-3 Precedence Values 

Value	List of Precedence Values
<0-7>	IP precedence value
critical	Critical precedence (5)
flash	Flash precedence (3)
flash-override	Flash override precedence (4)
immediate	Immediate precedence (2)
internet	Internetwork control precedence (6)
network	Network control precedence (7)
priority	Priority precedence (1)
routine	Routine precedence (0)

SUMMARY STEPS

1. config t

2. policy-map [type qos] [match-first] policy-map-name

3. class [type qos] {class-map-name | class-default} [insert-before before-class-map-name]

4. set precedence precedence-value

DETAILED STEPS

	Command	Purpose
Step 1	config t Example: switch# config t switch(config)#	Enters configuration mode.
Step 2	policy-map [type qos] [match-first] policy-map-name Example: switch(config)# policy-map policy1 switch(config-pmap-qos)#	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.
Step 3	class [type qos] {class-map-name | class-default} [insert-before before-class-map-name] Example: switch(config-pmap-qos)# class class1 switch(config-pmap-c-qos)#	Creates a reference to class-map-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. Specify class-default to select all traffic not currently matched by classes in policy map.
Step 4	set precedence precedence-value Example: switch(config-pmap-c-qos)# set precedence 3 switch(config-pmap-c-qos)#	Sets the IP precedence value to precedence-value. The value can range from 0 to 7. You can enter one of the values shown in Table 4-3.

Use the show policy-map command to display the policy-map configuration:

switch# show policy-map policy1

Configuring CoS Marking

You can set the value of the CoS field in the high-order three bits of the VLAN ID Tag field in the IEEE 802.1Q header.

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Note You can set CoS only in egress policies.

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SUMMARY STEPS

1. config t

2. policy-map [type qos] [match-first] policy-map-name

3. class [type qos] {class-map-name | class-default} [insert-before before-class-map-name]

4. set cos cos-value

DETAILED STEPS

	Command	Purpose
Step 1	config t Example: switch# config t switch(config)#	Enters configuration mode.
Step 2	policy-map [type qos] [match-first] policy-map-name Example: switch(config)# policy-map policy1 switch(config-pmap-qos)#	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.
Step 3	class [type qos] {class-map-name | class-default} [insert-before before-class-map-name] Example: switch(config-pmap-qos)# class class1 switch(config-pmap-c-qos)#	Creates a reference to class-map-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. Specify class-default to select all traffic not currently matched by classes in the policy map.
Step 4	set cos cos-value Example: switch(config-pmap-c-qos)# set cos 3 switch(config-pmap-c-qos)#	Sets the CoS value to cos-value. The value can range from 0 to 7. You can use this command only in egress policies.

Use the show policy-map command to display the policy-map configuration:

switch# show policy-map policy1

Configuring QoS Group Marking

You can set the value of the internal label QoS group, which is only locally significant. You can reference this value in subsequent policy actions or classify traffic that is referenced in egress policies by using the match qos-group class-map command.

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Note You can set QoS group only in ingress policies.

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SUMMARY STEPS

1. config t

2. policy-map [type qos] [match-first] policy-map-name

3. class [type qos] {class-map-name | class-default} [insert-before before-class-map-name]

4. set qos-group qos-group-value

DETAILED STEPS

	Command	Purpose
Step 1	config t Example: switch# config t switch(config)#	Enters configuration mode.
Step 2	policy-map [type qos] [match-first] policy-map-name Example: switch(config)# policy-map policy1 switch(config-pmap-qos)#	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.
Step 3	class [type qos] {class-map-name | class-default} [insert-before before-class-map-name] Example: switch(config-pmap-qos)# class class1 switch(config-pmap-c-qos)#	Creates a reference to class-map-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. Specify class-default to select all traffic not currently matched by classes in the policy map.
Step 4	set qos-group qos-group-value Example: switch(config-pmap-c-qos)# set qos-group 100 switch(config-pmap-c-qos)#	Sets the QoS group value to qos-group-value. The value can range from 0 to 126.

Use the show policy-map command to display the policy-map configuration:

switch# show policy-map policy1

Configuring Discard Class Marking

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Note If you configure this value, you cannot configure the DSCP value (see the "Configuring DSCP Marking" section).

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You can set the value of the internal label discard class, which is locally significant only. You can reference this value in subsequent policy actions or classify traffic that is referenced in egress policies by using the match discard-class class-map command.

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Note You can set the discard class only in ingress policies.

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SUMMARY STEPS

1. config t

2. policy-map [type qos] [match-first] policy-map-name

3. class [type qos] {class-map-name | class-default} [insert-before before-class-map-name]

4. set discard-class discard-class-value

DETAILED STEPS

	Command	Purpose
Step 1	config t Example: switch# config t switch(config)#	Enters configuration mode.
Step 2	policy-map [type qos] [match-first] policy-map-name Example: switch(config)# policy-map policy1 switch(config-pmap-qos)#	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.
Step 3	class [type qos] {class-map-name | class-default} [insert-before before-class-map-name] Example: switch(config-pmap-qos)# class class1 switch(config-pmap-c-qos)#	Creates a reference to class-map-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. Specify class-default to select all traffic not currently matched by classes in the policy map.
Step 4	set discard-class discard-class-value Example: switch(config-pmap-c-qos)# set discard-class 40 switch(config-pmap-c-qos)#	Sets the discard class value to discard-class-value. The value can range from 0 to 63. Note See "Configuring Marking Using Table Maps" section for information on using table maps with marking.

Use the show policy-map command to display the policy-map configuration:

switch# show policy-map policy1

Configuring Ingress and Egress Marking

You can apply the marking instructions in a QoS policy map to ingress or egress packets by attaching that QoS policy map to an interface. To select ingress or egress, you specify either the input or output keyword in the service-policy command. For detailed instructions, see the "Attaching and Detaching a QoS Policy Action from an Interface" section on page 2-18.

Configuring DSCP Port Marking

You can set the DSCP value for each class of traffic defined in a specified ingress policy map.

The default behavior of the device is to preserve the DSCP value, or to trust DSCP. To make the port untrusted, change the DSCP value. Unless you configure a QoS policy and attach that policy to specified interfaces, the DSCP value is preserved.

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Note You can attach only one policy type qos map to each interface in each direction.

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SUMMARY STEPS

1. config t

2. policy-map [type qos] [match-first] policy-map-name

3. class [type qos] {class-map-name | class-default} [insert-before before-class-map-name]

4. set dscp-value

5. exit

6. class [type qos] {class-map-name | class-default} [insert-before before-class-map-name]

7. set dscp-value

8. exit

9. class [type qos] {class-map-name | class-default} [insert-before before-class-map-name]

10. set dscp-value

11. exit

12. exit

13. {[interface ethernet slot/port] | vlan-id]}

14. service-policy [type qos] {input | output} policy-map-name [no-stats]

DETAILED STEPS

	Command	Purpose
Step 1	config t Example: switch# config t switch(config)#	Enters configuration mode.
Step 2	policy-map [type qos] [match-first] policy-map-name Example: switch(config)# policy-map policy1 switch(config-pmap-qos)#	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.
Step 3	class [type qos] {class-map-name | class-default} [insert-before before-class-map-name] Example: switch(config-pmap)# class class1 switch(config-pmap-c-qos)#	Creates a reference to class-map-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. Specify class-default to select all traffic not matched by classes in the policy map so far.
Step 4	set dscp-value Example: switch(config-pmap-c-qos)# set dscp af31 switch(config-pmap-c-qos)#	Sets the DSCP value to dscp-value. Valid values are shown in Table 4-2.
Step 5	exit Example: switch(config-pmap-c-qos)# exit switch(config-pmap-qos)#	Returns to policy-map configuration mode.
Step 6	class [type qos] {class-map-name | class-default} [insert-before before-class-map-name] Example: switch(config-pmap-qos)# class class2 switch(config-pmap-c-qos)#	Creates a reference to class-map-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. Specify class-default to select all traffic not currently matched by classes in the policy map.
Step 7	set dscp-value Example: switch(config-pmap-c-qos)# set dscp af13 switch(config-pmap-c-qos)#	Sets the DSCP value to dscp-value. Valid values are shown in Table 4-2.
Step 8	exit Example: switch(config-pmap-c-qos)# exit switch(config-pmap-qos)#	Returns to policy-map configuration mode.
Step 9	class [type qos] {class-map-name | class-default} [insert-before before-class-map-name] Example: switch(config-pmap-qos)# class class-default switch(config-pmap-c-qos)#	Creates a reference to class-map-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. Specify class-default to select all traffic not currently matched by classes in policy map.
Step 10	set dscp-value Example: switch(config-pmap-c-qos)# set dscp af22 switch(config-pmap-c-qos)#	Sets the DSCP value to dscp-value. Valid values are shown in Table 4-2.
Step 11	exit Example: switch(config-pmap-c-qos)# exit switch(config-pmap-qos)#	Returns to policy-map configuration mode.
Step 12	exit Example: switch(config-pmap)# exit switch(config)#	Returns to configuration mode.
Step 13	interface ethernet slot/port Example: switch(config)# interface ethernet 1/1 switch(config-if)#	Enters interface mode to configure the Ethernet interface.
	vlan-id Example: switch(config)# vlan 101 switch(config-if)#	(Optional) Enters the VLAN mode on the specified VLAN.
Step 14	service-policy [type qos] {input | output} policy-map-name [no-stats] Example: switch(config-if)# service-policy input policy1 switch(config-if)#	Adds policy-map-name to the input packets of the interface. You can attach only one input policy and one output policy to an interface.

Use the show policy-map command to display the policy-map configuration:

switch# show policy-map policy1

Configuring Table Maps for Use in Marking

You can configure the system-defined table maps to define the mapping of values from a source QoS field to a destination QoS field. The source and destination fields are determined by the context of the table map in the set and police commands. For information about table maps, see the "Configuring Marking Using Table Maps" section.

Use the default command to define the destination value of unmapped source values. By default, unmapped values are copied to the destination value, so that the destination value is the same as the source value. In Cisco NX-OS Release 4.0.2 and later releases, the ignore variable for the default command is no longer supported.

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Note You can use only one of the system-defined, table maps in this procedure. For information on the system-defined table maps, see Chapter 2, "Using Modular QoS CLI."

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SUMMARY STEPS

1. config t

2. table-map table-map-name

3. from source-value to dest-value

4. Repeat Step 3 to map other values.

5. default {value | copy}

6. exit

DETAILED STEPS

	Command	Purpose
Step 1	config t Example: switch# config t switch(config)#	Enters configuration mode.
Step 2	table-map table-map-name Example: switch(config)# table-map cos-dscp-map switch(config-tmap)#	Accesses the default, or system-defined, table map named table-map-name, and then enters table-map mode.
Step 3	from source-value to dest-value Example: switch(config-tmap)# from 0 to 2 switch(config-tmap)#	Defines a mapping from source-value to dest-value. Up to 64 mappings can be defined. The mapping values can be from 0 to 63.
Step 4	Repeat Step 3 to define more values.	—
Step 5	default {value | copy} Example: switch(config-tmap)# default 18 switch(config-tmap)#	Defines the default value to use for unmapped source values. The value must be in the range 0 to 63. Entering copy specifies the default copy action. Note In Cisco NX-OS 4.0.2 and later releases, the ignore variable for this is not supported.
Step 6	exit Example: switch(config-tmap)# exit switch(config)#	Exits table-map mode and enters configuration mode.

Use the show table-map command to display the table-map configuration:

switch# show table-map cos-dscp-map

Configuring Marking Using Table Maps

You can use the system-defined table maps to perform marking in the set and police policy map class commands.

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Note See Chapter 2, "Using Modular QoS CLI" for the list of system-defined table maps.

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A source field and destination field are specified in the command that maps to the source and destination values supplied in the referenced table map. The QoS fields that can be used in these commands are listed in Table 4-4.

Table 4-4 QoS Table Map Fields 

QoS Table Map Field	Description
CoS	Class of Service field in the 802.1Q header.
DSCP	Differentiated Services Code Point in the IP header.
IP precedence	Bits 0-2 of the IPv4 ToS field.
Discard class	Locally significant values that can be matched and manipulated within the system. The range is from 0 to 63.

You can use the system-defined markdown table maps for the exceed or violate action of the police command by using the same syntax as the set command.

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Note•The internal label QoS group is not supported through table maps.

•Marking down in the police command requires the use of a table map.

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For information on the police command, see Chapter 6, "Configuring Policing."

SUMMARY STEPS

1. config t

2. policy-map [type qos] [match-first] policy-map-name

3. class [type qos] {class-map-name | class-default} [insert-before before-class-map-name]

4. set {cos | dscp | discard-class | precedence | discard-class} {cos | dscp | discard-class | precedence | discard-class} table-map-name

5. exit

DETAILED STEPS

	Command	Purpose
Step 1	config t Example: switch# config t switch(config)#	Enters configuration mode.
Step 2	policy-map [type qos] [match-first] policy-map-name Example: switch(config)# policy-map policy1 switch(config-pmap-qos)#	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.
Step 3	class [type qos] {class-map-name | class-default} [insert-before before-class-map-name] Example: switch(config-pmap-qos)# class class1 switch(config-pmap-c-qos)#	Creates a reference to class-map-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. Specify class-default to select all traffic not currently matched by classes in the policy map.
Step 4	set {cos | dscp | discard-class | precedence | discard-class} {cos | dscp | discard-class| precedence | discard-class} table-map-name Example: switch(config-pmap-c-qos)# set cos dscp cos-dscp-map switch(config-pmap-c-qos)#	Sets the first packet field to the value of the second packet field based on the mapping values specified in the referenced table-map-name. Note The table-map-name must be the name of one of the system-defined table maps listed in Chapter 2, "Using Modular QoS CLI." You cannot use the name of a user-defined table in this procedure. The example shows that CoS is replaced by DSCP based on the system-defined cos-dscp-map.
Step 5	exit Example: switch(config-pmap-c)# exit switch(config-pmap-qos)#	Returns to policy-map configuration mode.

Use the show policy-map and show table-map cos-dscp-map command to display the policy1 policy-map configuration:

switch# show policy-map policy

Verifying the Marking Configuration

Use the show table-map and show policy-map commands to verify the marking configuration.

This command displays all table maps:

switch# show table-map

...

This command displays all policy maps:

switch# show policy-map

...

Example Configuration

The following example shows how to configure marking:

config t

  policy-map type qos untrust_dcsp

   class class-default

     set dscp 0

  policy-map type queuing untrust_1Gport_policy

   class type queuing 2q4t-in-q-default

     set cos 0

  policy-map type queuing untrust_10Gport_policy

   class type queuing 8q2t-in-q-default

     set cos 0

Feature History for Marking

Table 4-5 lists the release history for this feature.

Table 4-5 Feature History for Marking

Feature Name	Releases	Feature Information
Default command	4.0(2)	The ignore variable is no longer supported for the default command.
QoS Marking	4.0(1)	This feature was introduced.