Configuring Policing

This chapter describes how to configure policing of traffic classes on the Cisco NX-OS device. This chapter includes the following sections:

Information About Policing

Policing is the monitoring of the data rates for a particular class of traffic. When the data rate exceeds user-configured values, marking or dropping of packets occurs immediately. Policing does not buffer the traffic; therefore, the transmission delay is not affected. When traffic exceeds the data rate, you instruct the system to either drop the packets or mark QoS fields in them.

You can define single-rate, dual-rate, and color-aware policers.

Single-rate policers monitor the committed information rate (CIR) of traffic. Dual-rate policers monitor both CIR and peak information rate (PIR) of traffic. In addition, the system monitors associated burst sizes. Three colors, or conditions, are determined by the policer for each packet depending on the data rate parameters supplied: conform (green), exceed (yellow), or violate (red).

You can configure only one action for each condition. For example, you might police for traffic in a class to conform to the data rate of 256000 bits per second, with up to 200 millisecond bursts. The system would apply the conform action to traffic that falls within this rate, and it would apply the violate action to traffic that exceeds this rate.

Color-aware policers assume that traffic has been previously marked with a color. This information is then used in the actions taken by this type of policer.

For more information about policers, see RFC 2697 and RFC 2698 .

Shared Policers

QoS applies the bandwidth limits specified in a shared policer cumulatively to all flows in the matched traffic. A shared policer applies the same policer to more than one interface simultaneously.

For example, if you configure a shared policer to allow 1 Mbps for all Trivial File Transfer Protocol (TFTP) traffic flows on VLAN 1 and VLAN 3, the device limits the TFTP traffic for all flows combined on VLAN 1 and VLAN 3 to 1 Mbps.

The following are guidelines for configuring shared policers:

  • You create named shared policers by entering the qos shared-policer command. If you create a shared policer and create a policy using that shared policer and attach the policy to multiple ingress ports, the device polices the matched traffic from all the ingress ports to which it is attached.
  • You define shared policers in a policy map class within the police command. If you attach a named shared policer to multiple ingress ports, the device polices the matched traffic from all the ingress ports to which it is attached.
  • Shared policing works independently on each module.

Licensing Requirements for Policing

The following table shows the licensing requirements for this feature:

 

Product
License Requirement

Cisco NX-OS

The QoS feature does not require a 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 Cisco NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide .

However, using virtual device contexts (VDCs) requires an Advanced Services license.

Prerequisites for Policing

Policing has the following prerequisites:

  • You must be familiar with Chapter3, “Using Modular QoS CLI”
  • You are logged on to the switch.
  • You are in the correct 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

Policing has the following guidelines and limitations:

  • Each module polices independently, which might affect QoS features that are being applied to traffic that is distributed across more than one module. The following are examples of these QoS features:

– Policers applied to a port channel interface.

– Egress policers applied to a Layer 3 interface. The device performs egress policing decisions at the ingress interface, on the ingress module.

– Policers applied to a VLAN.

  • All policers in either the ingress or egress direction must use the same mode. For example, if the color-aware mode is needed for a class, all classes in that policy in the same direction must be in the color-aware mode.
  • Ingress policing is not supported on FEX host ports.

Configuring Policing

You can configure a single- or dual-rate policer.

This section includes the following topics:

 

Configuring 1-Rate and 2-Rate, 2-Color and 3-Color Policing

The type of policer created by the device is based on a combination of the police command arguments described in Table 6-1 .

Note You must specify the identical value for pir and cir to configure 1-rate 3-color policing.

 

Table 6-1 Arguments to the police Command

Argument
Description

cir

Committed information rate, or desired bandwidth, specified as a bit rate or a percentage of the link rate. Although a value for cir is required, the argument itself is optional. The range of values is from 1 to 80000000000. The range of policing values that are mathematically significant is from 8000 to 80 Gbps.

percent

Rate as a percentage of the interface rate. The range of values is from 1 to 100 percent.

bc

Indication of how much the cir can be exceeded, either as a bit rate or an amount of time at cir . The default is 200 milliseconds of traffic at the configured rate. The default data rate units are bytes, and the Gigabit per second (gbps) rate is not supported for this parameter.

pir

Peak information rate, specified as a PIR bit rate or a percentage of the link rate. There is no default. The range of values is from 1 to 80000000000; the range of policing values that are mathematically significant is 8000 to 80 Gbps. The range of percentage values is from 1 to 100 percent.

be

Indication of how much the pir can be exceeded, either as a bit rate or an amount of time at pir . When the bc value is not specified, the default is 200 milliseconds of traffic at the configured rate. The default data rate units are bytes, and the Gigabit per second (gbps) rate is not supported for this parameter.

Note You must specify a value for pir before the device displays this argument.

conform

Single action to take if the traffic data rate is within bounds. The basic actions are transmit or one of the set commands listed in Table 6-4 . The default is transmit.

exceed

Single action to take if the traffic data rate is exceeded. The basic actions are drop or markdown. The default is drop.

violate

Single action to take if the traffic data rate violates the configured rate values. The basic actions are drop or markdown. The default is drop.

Note For information on the color-aware police command arguments, see the “Configuring Color-Aware Policing” section.

Although all the arguments in Table 6-1 are optional, you must specify a value for cir . In this section, cir indicates its value but not necessarily the keyword itself. The combination of these arguments and the resulting policer types and actions are shown in Table 6-2 .

 

Table 6-2 Policer Types and Actions from Police Arguments Present

Police Arguments Present
Policer Type
Policer Action

cir , but not pir , be , or violate

1-rate, 2-color

≤ cir , conform ; else violate

 

cir and pir

1-rate, 3-color

≤ cir , conform ; ≤ pir , exceed ; else violate

Note You must specify identical values for cir and pir.

cir and pir

2-rate, 3-color

≤ cir , conform ; ≤ pir , exceed ; else violate

The policer actions that you can specify are described in Table 6-3 and Table 6-4 .

 

Table 6-3 Policer Actions for Exceed or Violate
Action
Description

drop

Drops the packet. This is only available when the packet exceeds or violates the parameters.

set dscp dscp table { cir-markdown-map | pir-markdown-map }

Sets the specified fields from a table map and transmits the packet. For more information on the system-defined, or default table maps, see Chapter4, “Configuring Marking” This is available only when the packet exceeds the parameters (use the cir-markdown-map) or violates the parameters (use the pir-markdown-map).

 

Table 6-4 Policer Actions for Conform
Action
Description

transmit

Transmits the packet. This is available only when the packet conforms to the parameters.

set-prec-transmit

Sets the IP precedence field to a specified value and transmits the packet. This is available only when the packet conforms to the parameters.

set-dscp-transmit

Sets the Differentiated Service Code Point (DSCP) field to a specified value and transmits the packet. This is available only when the packet conforms to the parameters

set-cos-transmit

Sets the class of service (CoS) field to a specified value and transmits the packet. This is available only when the packet conforms to the parameters

set-qos-transmit

Sets the QoS group internal label to specified value and transmits the packet. This action can be used only in input policies and is available only when the packet conforms to the parameters

set-discard-class-transmit

Sets the discard-class internal label to a specified value and transmits the packet. This action can be used only in ingress policies and is available only when the packet conforms to the parameters

Note The policer can only drop or mark down packets that exceed or violate the specified parameters. For information on marking down packets, see Chapter4, “Configuring Marking”

The data rates used in the police command are described in Table 6-5 .

 

Table 6-5 Data Rates for the police Command

Rate
Description

bps

Bits per second (default)

kbps

1,000 bits per seconds

mbps

1,000,000 bits per second

gbps

1,000,000,000 bits per second

Burst sizes used in the police command are described in Table 6-6 .

 

Table 6-6 Burst Sizes for the police Command

Speed
Description

bytes

bytes

kbytes

1,000 bytes

mbytes

1,000,000 bytes

ms

milliseconds

us

microseconds

SUMMARY STEPS

You must specify the identical value for pir and cir to configure 1-rate 3-color policing.

1. config t

2. policy-map [ type qos ] [ match-first ] { qos-policy-map-name | qos-dynamic }

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

4. police [ cir ] { committed-rate [ data-rate ] | percent cir-link-percent } [ bc committed-burst-rate [ link-speed ]] [ pir ] { peak-rate [ data-rate ] | percent cir-link-percent } [ be peak-burst-rate [ link-speed ]] { conform { transmit | set-prec-transmit | set-dscp-transmit | set-cos-transmit | set-qos-transmit | set-discard-class-transmit } [ exceed { drop | set dscp dscp table { cir-markdown-map }} [ violate { drop | set dscp dscp table { pir-markdown-map }}]]}

5. exit

6. exit

7. show policy-map [ type qos ] [ policy-map-name | qos-dynamic ]

8. copy running-config startup-config

Note A 1-rate 2-color policer with the violate markdown action is not supported.

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 ] [ qos-policy-map-name | qos-dynamic ]

 

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 | qos-dynamic | 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. Use the class-default keyword to select all traffic that is not currently matched by classes in the policy map.

Step 4

police [ cir ] { committed-rate [ data-rate ] | percent cir-link-percent } [ bc committed- burst-rate [ link-speed ]][ pir ] { peak-rate [ data-rate ] | percent cir-link-percent } [ be peak-burst-rate [ link-speed ]] [ conform { transmit | set-prec-transmit | set-dscp-transmit | set-cos-transmit | set-qos-transmit | set-discard-class-transmit } [ exceed { drop | set dscp dscp table { cir-markdown-map }} [ violate { drop | set dscp dscp table { pir-markdown-map }}]]}

 

Example:

switch(config-pmap-c-qos)# police cir 256000 pir 256000 conform transmit exceed set dscp dscp table cir-markdown-map violate drop

switch(config-pmap-c-qos)#

 

 

 

Polices cir in bits or as a percentage of the link rate. The conform action is taken if the data rate is ≤ cir . If be and pir are not specified, all other traffic takes the violate action. If be or violate are specified, the exceed action is taken if the data rate ≤ pir , and the violate action is taken otherwise. The actions are described in Table 6-3 and Table 6-4 . The data rates and link speeds are described in Table 6-5 and Table 6-6 .

 

 

This example shows a 1-rate, 3-color policer that transmits if the data rate is within 200 milliseconds of traffic at 256000 bps, marks DSCP to 6 if the data rate is within 300 milliseconds of traffic at 256000 bps, and drops packets otherwise.

Note You must specify identical values for cir and pir.

Step 5

exit

 

Example:

switch(config-pmap-c-qos)# exit

switch(config-pmap-qos)#

Exits policy-map class configuration mode and enters policy-map mode.

Step 6

exit

 

Example:

switch(config-pmap-qos)# exit

switch(config)#

Exits policy-map mode and enters configuration mode.

Step 7

show policy-map [ type qos ] [ policy-map-name | qos-dynamic ]

 

Example:

switch(config)# show policy-map

(Optional) Displays information about all configured policy maps or a selected policy map of type qos.

Step 8

copy running-config startup-config

 

Example:

switch(config)# copy running-config startup-config

(Optional) Saves the running configuration to the startup configuration.

Use the show policy-map command to display the policy1 policy-map configuration as shown below:

switch# show policy-map policy1

Configuring Color-Aware Policing

Color-aware policing implies that the QoS DSCP field in a class of traffic has been previously marked with values that you can use in a policer. This feature allows you to mark traffic at one node in a network and then take action based on this marking at a subsequent node.

Note For information on the police command, see the “Configuring 1-Rate and 2-Rate, 2-Color and 3-Color Policing” section.

You can use one or more of the four police command class maps conform-color or exceed-color to perform color-aware policing. These keywords require a class-map name that is used to classify packets. Based on the match criteria that you specify in the class maps, the traffic is classified into one of these two classes or class-default if there is no match. The policer then takes the following action:

  • Packets that belong to the conform-color class are policed with the cir and pir arguments to the police command.
  • Packets that belong to the exceed-color class are policed only against the pir argument to the police command. If pir is not specified, the cir values are used.
  • Packets that end up in class-default because they fail to match either the conform-color or exceed-color class will immediately take the violate action.

Note A color other than class-default cannot be assigned to the violate action because according to RFC 2697 and RFC 2698, all packets must be assigned a color.

You can set the DSCP value for color-aware policing to a specified value. The list of valid DSCP values is shown in Table 6-7 .

 

Table 6-7 Color-Aware Policing Valid 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

After you apply color-aware policing, all matching packets in the device will be policed according to the specifications of the color-aware policer.

To configure color-aware policing, follow these steps:

Step 1 Create the class map. For information about configuring class maps, see Chapter2, “Configuring Classification”

Step 2 Create a policy map. For information about policy maps, see this chapter and Chapter3, “Using Modular QoS CLI”

Step 3 Configure the color-aware class map as described in this section.

Step 4 Apply the service policy to the interfaces. For information about attaching policies to interfaces, see Chapter3, “Using Modular QoS CLI”

Note The rates specified in the shared policer are shared by the number of interfaces to which you apply the service policy. Each interface does not have its own dedicated rate as specified in the shared policer.

 

SUMMARY STEPS

1. config t

2. class-map { conform-color-in | conform-color-out | exceed-color-in | exceed-color-out }

3. match dscp dscp-value

4. policy-map [ type qos ] [ match-first ] { qos-policy-map-name | qos-dynamic }

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

6. police [ cir ] { committed-rate [ data-rate ] | percent cir-link-percent } [ bc committed-burst-rate [ link-speed ]] [ pir ] { peak-rate [ data-rate ] | percent cir-link-percent } [ be peak-burst-rate [ link-speed ]] { conform { transmit | set-prec-transmit | set-dscp-transmit | set-cos-transmit | set-qos-transmit | set-discard-class-transmit } [ exceed { drop | set dscp dscp table { cir-markdown-map }} [ violate { drop | set dscp dscp table { pir-markdown-map }}]]}

7. exit

8. show policy-map [ policy-map-name | qos-dynamic ]

9. copy running-config startup-config

DETAILED STEPS

 

 
Command
Purpose

Step 1

config t

 

Example:

switch# config t

switch(config)#

Enters configuration mode.

Step 2

class-map { conform-color-in | conform-color-out | exceed-color-in | exceed-color-out }

 

Example:

switch(config)# class-map conform-color-in

switch(config-color-map)#

Accesses the color-aware class map, and enters color-map mode. When you enter this command, the system returns the following message:

Warning: Configuring match for any DSCP values in this class-map will make ALL policers in the system color-aware for those DSCP values .

Step 3

match dscp dscp-value

 

Example:

switch(config-color-map)# match dscp af22

switch(config-color-map)#

Specifies the DSCP value to match for color-aware policers. See Table 6-7 for a list of valid values.

Step 4

policy-map [ type qos ] [ match-first ] [ qos-policy-map-name | qos-dynamic ]

 

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 5

class [ type qos ] { class-map-name | qos-dynamic | 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. Use the class-default keyword to select all traffic that is not currently matched by classes in the policy map.

Step 6

police [ cir ] { committed-rate [ data-rate ] | percent cir-link-percent } [ bc committed- burst-rate [ link-speed ][ pir ] { peak-rate [ data-rate ] | percent cir-link-percent } [ be peak-burst-rate [ link-speed ] [ conform { transmit | set-prec-transmit | set-dscp-transmit | set-cos-transmit | set-qos-transmit | set-discard-class-transmit } [ exceed { drop | set dscp dscp table { cir-markdown-map }} [ violate { drop | set dscp dscp table { pir-markdown-map }}]]]

 

Example #1:

switch(config-pmap-c-qos)# police cir 256000 be 300 ms conform-class my_conform_class_map exceed-class my_exceed_class_map conform transmit exceed set dscp dscp table cir-markdown-map violate drop

switch(config-pmap-c-qos)#

 

Example #2:

switch(config-pmap-c-qos)# police cir 256000 pir 512000 conform-class my_conform_class_map exceed-class my_exceed_class_map conform transmit exceed set dscp dscp table cir-markdown-map violate drop

switch(config-pmap-c-qos)#

Polices cir in bits or as a percentage of the link rate. The conform action is taken if the data rate is ≤ cir . If be and pir are not specified, all other traffic takes the violate action. If be or violate are specified, the exceed action is taken if the data rate ≤ pir , and the violate action is taken otherwise. The actions are described in Table 6-3 and Table 6-4 . The data rates and link speeds are described in Table 6-5 and Table 6-6 .

 

 

 

This first example shows a 1-rate, 3-color color-aware policer that transmits if the conform-class data rate is within 200 milliseconds of traffic at 256000 bps, marks DSCP to 6 if the exceed-class data rate is within 300 milliseconds of traffic at 256000 bps, and drops packets otherwise.

 

This second example shows a 2-rate, 3-color color-aware policer that transmits if the data rate is within 200 milliseconds of traffic at 256000 bps, marks CoS to 5 if the data rate exceeds 200 milliseconds of traffic at 512 bps, and drops packets otherwise.

Step 7

exit

 

Example:

switch(config-color-map)# exit

switch(config)#

Exits color-map mode and then enters configuration mode.

Step 8

show policy-map [ type qos ] [ policy-map-name | qos-dynamic ]

 

Example:

switch(config)# show policy-map

(Optional) Displays information about all configured policy maps or a selected policy map of type qos.

Step 9

copy running-config startup-config

 

Example:

switch(config)# copy running-config startup-config

(Optional) Saves the running configuration to the startup configuration.

This example shows how to display the policy1 policy-map configuration:

switch# show policy-map policy1

Configuring Ingress and Egress Policing

You can apply the policing 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 more information on attaching and detaching a QoS policy action from an interface, see the Chapter3, “Using Modular QoS CLI”

Configuring Markdown Policing

Markdown policing is the setting of a QoS field in a packet when traffic exceeds or violates the policed data rates. You can configure markdown policing by using the set commands for policing action described in Table 6-3 and Table 6-4 .

The example in this section shows you how to use a table map to perform a markdown.

SUMMARY STEPS

1. config t

2. policy-map [ type qos ] [ match-first ] { qos-policy-map-name | qos-dynamic }

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

4. police [ cir ] { committed-rate [ data-rate ] | percent cir-link-percent } [ bc committed-burst-rate [ link-speed ]] [ pir ] { peak-rate [ data-rate ] | percent cir-link-percent } [ be peak-burst-rate [ link-speed ]] { conform conform-action [ exceed { drop | set dscp dscp table cir-markdown-map } [ violate { drop | set dscp dscp table pir-markdown-map }]]}}

5. exit

6. exit

7. show policy-map [ type qos ] [ policy-map-name | qos-dynamic ]

8. copy running-config startup-config

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 ] [qos-policy-map-name | qos-dynamic ]

 

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 | qos-dynamic | 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. Use the class-default keyword to select all traffic that is not currently matched by classes in the policy map.

Step 4

police [ cir ] { committed-rate [ data-rate ] | percent cir- link-percent } [[ bc | burst ] burst-rate [ link-speed ]] [[ be | peak-burst ] peak-burst-rate [ link-speed ]] [ conform conform-action [ exceed set dscp dscp table cir-markdown-map [ violate drop set dscp dscp table pir-markdown-map ]]}

 

 

 

 

Example:

switch(config-pmap-c-qos)# police cir 256000 be 300 ms conform transmit exceed set dscp dscp table cir-markdown-map violate drop

switch(config-pmap-c-qos)#

Polices cir in bits or as a percentage of the link rate. The conform action is taken if the data rate is ≤ cir . If be and pir are not specified, all other traffic takes the violate action. If be or violate are specified, the exceed action is taken if the data rate ≤ pir , and the violate action is taken otherwise. The actions are described in Table 6-3 and Table 6-4 . The data rates and link speeds are described in Table 6-5 and Table 6-6 .

 

This example shows a 1-rate, 3-color policer that transmits if the data rate is within 200 milliseconds of traffic at 256000 bps; marks down DSCP using the system-defined table map if the data rate is within 300 milliseconds of traffic at 256000 bps, and drops packets otherwise.

Step 5

exit

 

Example:

switch(config-pmap-c-qos)# exit

switch(config-pmap-qos)#

Exits policy-map class configuration mode and enters policy-map mode.

Step 6

exit

 

Example:

switch(config-pmap-qos)# exit

switch(config)#

Exits policy-map mode and enters configuration mode.

Step 7

show policy-map [ type qos ] [ policy-map-name | qos-dynamic ]

 

Example:

switch(config)# show policy-map

(Optional) Displays information about all configured policy maps or a selected policy map of type qos.

Step 8

copy running-config startup-config

 

Example:

switch(config)# copy running-config startup-config

(Optional) Saves the running configuration to the startup configuration.

Use the show policy-map command to display the policy1 policy-map configuration as shown below:

switch# show policy-map policy1
 

Configuring Shared Policers

The shared-policer feature allows you to apply the same policing parameters to several interfaces simultaneously. You create a shared policer by assigning a name to a policer, and then applying that policer to a policy map that you attach to the specified interfaces. The shared policer is also referred to as the named aggregate policer in other Cisco documentation.

Note After you configure the shared policer, you can use the shared-policer name to configure any type of shared policing, as described in the “Configuring 1-Rate and 2-Rate, 2-Color and 3-Color Policing” section, the “Configuring Color-Aware Policing” section, the “Configuring Ingress and Egress Policing” section, and the “Configuring Markdown Policing” section.

To configure shared policing, follow these steps:

Step 1 Configure the shared policer as described in this section.

Step 2 Create the class map. For information about configuring class maps, see Chapter2, “Configuring Classification”

Step 3 Create a policy map. For information about policy maps, see this chapter and Chapter3, “Using Modular QoS CLI”

Step 4 Reference the shared policer to the policy map as described in this section.

Step 5 Apply the service policy to the interfaces. For information about attaching policies to interfaces, see Chapter3, “Using Modular QoS CLI”

Note The rates specified in the shared policer are shared by the number of interfaces to which you apply the service policy. Each interface does not have its own dedicated rate as specified in the shared policer.

 

SUMMARY STEPS

1. config t

2. qos shared-policer [ type qos ] shared-policer-name [ cir ] { committed-rate [ data-rate ] | percent cir-link-percent } [ bc committed-burst-rate [ link-speed ]] [ pir ] { peak-rate [ data-rate ] | percent cir-link-percent } [ be peak-burst-rate [ link-speed ]] {{ conform conform-action [ exceed { drop | set dscp dscp table cir-markdown-map } [ violate { drop | set dscp dscp table pir-markdown-map }]]}

3. policy-map [ type qos ] [ match-first ] { qos-policy-map-name | qos-dynamic }

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

5. police aggregate shared-policer-name

6. exit

7. exit

8. show qos shared-policer [ shared-policer-name ]

9. copy running-config startup-config

DETAILED STEPS

 

 
Command
Purpose

Step 1

config t

 

Example:

switch# config t

switch(config)#

Enters configuration mode.

Step 2

qos shared-policer [ type qos ] shared-policer-name [ cir ] { committed-rate [ data-rate ] | percent cir-link-percent } [ bc committed- burst-rate [ link-speed ]][ pir ] { peak-rate [ data-rate ] | percent cir-link-percent } [ be peak-burst-rate [ link-speed ]] [ conform conform-action [ exceed { drop | set dscp dscp table cir-markdown-map [ violate set dscp dscp table pir-markdown-map }]]}

 

Example:

switch(config)# qos shared-policer test1 cir 10 mbps

switch(config)#

Creates or accesses the shared policer. The shared-policer-name can contain alphabetic, hyphen, or underscore characters, is case sensitive, and can be up to 40 characters. Polices cir in bits or as a percentage of the link rate. The conform action is taken if the data rate is ≤ cir . If be and pir are not specified, all other traffic takes the violate action. If be or violate are specified, the exceed action is taken if the data rate ≤ pir , and the violate action is taken otherwise. The actions are described in Table 6-3 and Table 6-4 . The data rates and link speeds are described in Table 6-5 and Table 6-6 .

Step 3

policy-map [ type qos ] [ match-first ] [ qos-policy-map-name | qos-dynamic ]

 

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 4

class [ type qos ] { class-map-name | qos-dynamic | 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. Use the class-default keyword to select all traffic that is not currently matched by classes in the policy map.

Step 5

police aggregate shared-policer-name

 

Example:

switch(config-pmap-c-qos)# police aggregate test1

switch(config-pmap-c-qos)#

Creates a reference in the policy map to shared-policer-name .

Step 6

exit

 

Example:

switch(config-pmap-c-qos)# exit

switch(config-pmap-qos)#

Exits policy-map class configuration mode and enters policy-map mode.

Step 7

exit

 

Example:

switch(config-pmap-qos)# exit

switch(config)#

Exits policy-map mode and enters configuration mode.

Step 8

show qos shared-policer [ shared-policer-name ]

 

Example:

switch(config)# show qos shared-policer test1

(Optional) Displays information about the configuration of all shared policers.

Step 9

copy running-config startup-config

 

Example:

switch(config)# copy running-config startup-config

(Optional) Saves the running configuration to the startup configuration.

Use the show qos shared-policer command to display the test1 shared-policer configurations as shown below:

switch# show qos shared-policer test1

Verifying the Policing Configuration

To display the policing configuration information, perform one of these tasks:

 

show policy-map

Displays information about policy maps and policing.

show qos shared-policer [ type qos ] [ policer-name ]

Displays information about all shared policing.

Examples for Policing

The following example shows how to configure policing for a 1-rate, 2-color policer:

config t
policy-map policy1
class one_rate_2_color_policer
police cir 256000 conform transmit violate drop
 

The following example shows how to configure policing for a 1-rate, 2-color policer with DSCP markdown:

config t
policy-map policy2
class one_rate_2_color_policer_with_dscp_markdown
police cir 256000 conform transmit violate drop
 

The following example shows how to configure policing for a 1-rate, 3-color policer:

config t
policy-map policy3
class one_rate_3_color_policer
police cir 256000 pir 256000 conform transmit exceed set dscp dscp table cir-markdown-map violate drop
 

The following example shows how to configure policing for a 2-rate, 3-color policer:

config t
policy-map policy4
class two_rate_3_color_policer
police cir 256000 pir 256000 conform transmit exceed set dscp dscp table cir-markdown-map violate drop
 

The following example shows how to configure policing for a color-aware policer for specified DSCP values:

config t
class-map conform-color-in
match dscp 0-10
policy-map policy5
class one_rate_2_color_policer
police cir 256000 conform transmit violate drop
 

The following example shows how to configure policing for a shared policer:

config t
qos shared-policer type qos udp_10mbps cir 10 mbps pir 20 mbps conform transmit exceed set dscp dscp table cir-markdown-map violate drop
policy-map type qos udp_policy
class type qos udp_qos
police aggregate udp_10mbps

Feature History for Policing

Table 6-8 lists the release history for this feature.

 

Table 6-8 Feature History for Policing
Feature Name
Releases
Feature Information

No change.

4.1(2)

—

No change

4.2(1)

—

No change

5.0(2)

—