Published On: August 6ᵗʰ, 2019 02:01

QoS: NBAR Configuration Guide, Cisco IOS XE Release 3S

After you enable Protocol Discovery, you can configure Network-Based Application Recognition (NBAR) using the functionality of the Modular Quality of Service (QoS) Command-Line Interface (CLI) (MQC). The MQC uses traffic classes and traffic policies (policy maps) to apply QoS features to classes of traffic and applications recognized by NBAR.

This module contains concepts and tasks for configuring NBAR using the MQC.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/​go/​cfn. An account on Cisco.com is not required.

Prerequisites for Configuring NBAR Using the MQC

  • Before configuring NBAR using the MQC, read the information in the "Classifying Network Traffic Using NBAR" module.

  • As applicable, enable Protocol Discovery and use it to obtain statistics about the protocols and applications that are used in your network. You will need this information when using the MQC.


Note


This prerequisite assumes that you do not already have this information about the protocols and applications in use in your network.


Information About NBAR Coarse-Grain Classification

NBAR and the MQC Functionality

To configure NBAR using the MQC, you must define a traffic class, configure a traffic policy (policy map), and then attach that traffic policy to the appropriate interface. These three tasks can be accomplished by using the MQC. The MQC is a command-line interface that allows you to define traffic classes, create and configure traffic policies (policy maps), and then attach these traffic policies to interfaces.

In the MQC, the class-map command is used to define a traffic class (which is then associated with a traffic policy). The purpose of a traffic class is to classify traffic.

Using the MQC to configure NBAR consists of the following:

  • Defining a traffic class with the class-map command.

  • Creating a traffic policy by associating the traffic class with one or more QoS features (using the policy-map command).

  • Attaching the traffic policy to the interface with the service-policy command.

A traffic class contains three major elements: a name, one or more match commands, and, if more than one match command exists in the traffic class, an instruction on how to evaluate these match commands (that is, match-all or match-any). The traffic class is named in the class-map command line; for example, if you enter the class-map cisco command while configuring the traffic class in the CLI, the traffic class would be named "cisco."

The match commands are used to specify various criteria for classifying packets. Packets are checked to determine whether they match the criteria specified in the match commands. If a packet matches the specified criteria, that packet is considered a member of the class and is forwarded according to the QoS specifications set in the traffic policy. Packets that fail to meet any of the matching criteria are classified as members of the default traffic class.


Note


For NBAR, the match protocol commands are used to specify the match criteria, as described in the NBAR and the match protocol Commands.


NBAR and the match protocol Commands

NBAR recognizes specific network protocols and network applications that are used in your network. Once a protocol or application is recognized by NBAR, you can use the MQC to group the packets associated with those protocols or applications into classes. These classes are grouped on the basis of whether the packets conform to certain criteria.

For NBAR, the criterion is whether the packet matches a specific protocol or application known to NBAR. Using the MQC, network traffic with one network protocol (citrix, for example) can be placed into one traffic class, while traffic that matches a different network protocol (gnutella, for example) can be placed into another traffic class. Later, the network traffic within each class can be given the appropriate QoS treatment by using a traffic policy (policy map).

You specify the criteria used to classify traffic by using a match protocolcommand. The table below lists some of the available match protocolcommands and the corresponding protocol or traffic type recognized and supported by NBAR.


Note


For a more complete list of the protocol types supported by NBAR, see the "Classifying Network Traffic Using NBAR" module.


Table 1 match protocol Commands and Corresponding Protocol or Traffic Type

match protocol Command1

Protocol Type

match protocol (NBAR)

Protocol type supported by NBAR

match protocol citrix

Citrix protocol

match protocol fasttrack

FastTrack peer-to-peer traffic

match protocol gnutella

Gnutella peer-to-peer traffic

match protocol http

Hypertext Transfer Protocol

match protocol rtp

Real-Time Transport Protocol traffic

match protocol unknown [final]

All unknown and/or unclassified traffic

1 Cisco IOS match protocol commands can vary by release. For more information, see the command documentation for the Cisco IOS release that you are using.

How to Configure NBAR Using the MQC

Configuring DSCP-Based Layer 3 Custom Applications

SUMMARY STEPS

1. enable

2. configure terminal

3. ip nbar custom name transport tcp id id

4. ip nbar custom name transport udp-tcp

5. dscp dscp-value

6. exit


DETAILED STEPS
  Command or Action Purpose
Step 1 enable


Example:
Device> enable
 

Enables privileged EXEC mode.

  • Enter your password if prompted.

 
Step 2 configure terminal


Example:
Device# configure terminal
 

Enters global configuration mode.

 
Step 3 ip nbar custom name transport tcp id id


Example:
Device(config)# ip nbar custom mycustom transport tcp id 100
 
Specifies TCP or UDP as the transport protocol and enters custom configuration mode.  
Step 4 ip nbar custom name transport udp-tcp


Example:
Device(config)# ip nbar custom mycustom transport udp-tcp 
 
Specifies TCP and UDP as the transport protocol and enters custom configuration mode.  
Step 5 dscp dscp-value


Example:
Device(config-custom)# dscp ef
 

Specifies the differentiated service code points (DSCP) value.

Note   

In cases where two custom applications have the same filters, the priority is set according to the order of configuration.

 
Step 6 exit


Example:
Device(config-custom)# exit
 
Exits custom configuration mode.  

Managing Unclassified and Unknown Traffic

Some protocols require the analysis of more than one packet for NBAR classification. So packets sent until such a classification occurs are considered unknown. unknown final excludes these temporarily classified packets, and includes only those packets that are determined as unknown after the NBAR classification process.

By default, all traffic not matched to the unknown, are matched to a default class, as is the case with MQC.

Before You Begin

Ensure that NBAR is fully configured (i.e Protocol Discovery and others). If NBAR is configured to match only a partial set of protocols, then all inactivate protocols are considered as unclassified traffic and hence unknown.

SUMMARY STEPS

1. enable

2. configure terminal

3. class-map [match-all | match-any] unknown

4. match protocol unknown [final]

5. end


DETAILED STEPS
  Command or Action Purpose
Step 1 enable


Example:
Device> enable
 

Enables privileged EXEC mode.

  • Enter your password if prompted.

 
Step 2 configure terminal


Example:
Device# configure terminal
 

Enters global configuration mode.

 
Step 3 class-map [match-all | match-any] unknown


Example:
Device(config)# class-map match-all my-unknown
 

Creates a class map to be used for matching unknown traffic to a new class and enters class-map configuration mode.

 
Step 4 match protocol unknown [final]


Example:
Device(config-cmap)# match protocol unknown final
 

Configures NBAR to match unknown traffic.

  • The unknown keyword signifies any traffic that is unclassified

  • The unknown final signifies traffic that is determined by NBAR as unknown.

 
Step 5 end


Example:
Device(config-cmap)# end
 

(Optional) Returns to privileged EXEC mode.

 

You can now configure the following tasks

  1. Configuring a Traffic Policy

  2. Attaching a Traffic Policy to an Interface or sub-interface

Configuring a Traffic Policy

Traffic that matches a user-specified criterion can be organized into a specific class that can, in turn, receive specific user-defined QoS treatment when that class is included in a policy map.

To configure a traffic policy, perform the following steps.


Note


The bandwidth command is shown in Step 5. The bandwidth command configures the QoS feature class-based weighted fair queuing (CBWFQ). CBWFQ is just an example of a QoS feature that can be configured. Use the appropriate command for the QoS feature that you want to use. As of Cisco IOS Release 12.2(18)ZY, CBWFQ is not supported on the Catalyst 6500 series switch that is equipped with a Supervisor 32/programmable intelligent services accelerator (PISA).



Note


For Cisco IOS Release 12.2(18)ZY, an existing traffic policy (policy map) cannot be modified if the traffic policy is already attached to the interface. To remove the policy map from the interface, use the no form of the service-policy command.

>
SUMMARY STEPS

1. enable

2. configure terminal

3. policy-map policy-map-name

4. class {class-name | class-default}

5. bandwidth {bandwidth-kbps| remaining percent percentage| percent percentage}

6. end


DETAILED STEPS
  Command or Action Purpose
Step 1 enable


Example:
Device> enable
 

Enables privileged EXEC mode.

  • Enter your password if prompted.

 
Step 2 configure terminal


Example:
Device# configure terminal
 

Enters global configuration mode.

 
Step 3 policy-map policy-map-name


Example:
Device(config)# policy-map policy1
 

Creates or modifies a policy map that can be attached to one or more interfaces and enters policy-map configuration mode.

  • Enter the name of the policy map.

 
Step 4 class {class-name | class-default}


Example:
Device(config-pmap)# class class1
 

Specifies the name of the class whose policy you want to create or change and enters policy-map class configuration mode.

  • Enter the specific class name or enter the class-defaultkeyword.

 
Step 5 bandwidth {bandwidth-kbps| remaining percent percentage| percent percentage}


Example:
Device(config-pmap-c)# bandwidth percent 50 


Example:
 

(Optional) Specifies or modifies the bandwidth allocated for a class belonging to a policy map.

  • Enter the amount of bandwidth as a number of kbps, a relative percentage of bandwidth, or an absolute amount of bandwidth.

Note   

The bandwidth command configures the QoS feature class-based weighted fair queuing (CBWFQ). CBWFQ is just an example of a QoS feature that can be configured. Use the appropriate command for the QoS feature that you want to use.

Note   

As of Cisco IOS Release 12.2(18)ZY, CBWFQ is not supported on the Catalyst 6500 series switch that is equipped with a Supervisor 32/PISA.

 
Step 6 end


Example:
Device(config-pmap-c)# end
 

(Optional) Returns to privileged EXEC mode.

 

Attaching a Traffic Policy to an Interface or Subinterface

After a policy map is created, the next step is to attach the traffic policy (sometimes called a policy map) to an interface or subinterface. Traffic policies can be attached to either the input or output direction of the interface or subinterface.


Note


Depending on the needs of your network, you may need to attach the traffic policy to an ATM PVC, a Frame Relay data-link connection identifier (DLCI), or other type of interface.


To attach a traffic policy (policy map) to an interface, perform the following steps.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface type number [name-tag]

4. pvc [name] vpi / vci [ilmi| qsaal| smds| l2transport]

5. exit

6. service-policy {input | output} policy-map-name

7. end


DETAILED STEPS
  Command or Action Purpose
Step 1 enable


Example:
Device> enable
 

Enables privileged EXEC mode.

  • Enter your password if prompted.

 
Step 2 configure terminal


Example:
Device# configure terminal
 

Enters global configuration mode.

 
Step 3 interface type number [name-tag]


Example:
Device(config)# interface ethernet 2/4 
 

Configures an interface type and enters interface configuration mode.

  • Enter the interface type and the interface number.

 
Step 4 pvc [name] vpi / vci [ilmi| qsaal| smds| l2transport]


Example:
Device(config-if)# pvc cisco 0/16
 

(Optional) Creates or assigns a name to an ATM permanent virtual circuit (PVC), specifies the encapsulation type on an ATM PVC, and enters ATM virtual circuit configuration mode.

  • Enter the PVC name, the ATM network virtual path identifier, and the network virtual channel identifier.

Note   

This step is required only if you are attaching the policy map to an ATM PVC. If you are not attaching the policy map to an ATM PVC, advance to Step 6 .

 
Step 5 exit


Example:
Device(config-atm-vc)# exit
 

(Optional) Returns to interface configuration mode.

Note   

This step is required only if you are attaching the policy map to an ATM PVC and you completed Step 4 . If you are not attaching the policy map to an ATM PVC, advance to Step 6 .

 
Step 6 service-policy {input | output} policy-map-name


Example:
Device(config-if)# service-policy input policy1 
 

Attaches a policy map (traffic policy) to an input or output interface.

  • Specify either the input or output keyword, and enter the policy map name.

Note   

Policy maps can be configured on ingress or egress Devices. They can also be attached in the input or output direction of an interface. The direction (input or output) and the Device (ingress or egress) to which the policy map should be attached vary according your network configuration. When using the service-policy command to attach the policy map to an interface, be sure to choose the Device and the interface direction that are appropriate for your network configuration.

Note   

After you use the service-policy command, you may see two messages similar to the following:

%PISA-6-NBAR_ENABLED: feature accelerated on input direction of: [interface name and type
]
%PISA-6-NBAR_ENABLED: feature accelerated on output direction of: [interface name and type

While both of these messages appear, NBAR is enabled in the direction specified by the input or output keyword only.

 
Step 7 end


Example:
Device(config-if)# end
 

(Optional) Returns to privileged EXEC mode.

 

Verifying NBAR Using the MCQ

After you create the traffic classes and traffic policies (policy maps), you may want to verify that the end result is the one you intended. That is, you may want to verify whether your traffic is being classified correctly and whether it is receiving the QoS treatment as intended. You may also want to verify that the protocol-to-port mappings are correct.

To verify the NBAR traffic classes, traffic policies, and protocol-to-port mappings, perform the following steps.

SUMMARY STEPS

1. show class-map [class-map-name]

2. show policy-map [policy-map]

3. show policy-map interface type number

4. show ip nbar port-map [protocol-name]


DETAILED STEPS
  Command or Action Purpose
Step 1 show class-map [class-map-name]


Example:
Device# show class-map
 

(Optional) Displays all class maps and their matching criteria.

  • (Optional) Enter the name of a specific class map.

 
Step 2 show policy-map [policy-map]


Example:
Device# show policy-map
 

(Optional) Displays the configuration of all classes for a specified service policy map or all classes for all existing policy maps.

  • (Optional) Enter the name of a specific policy map.

 
Step 3 show policy-map interface type number


Example:
Device# show policy-map interface Fastethernet 6/0
 

(Optional) Displays the packet and class statistics for all policy maps on the specified interface.

  • Enter the interface type and the interface number.

 
Step 4 show ip nbar port-map [protocol-name]


Example:
Device# show ip nbar port-map
 

(Optional) Displays the current protocol-to-port mappings in use by NBAR.

  • (Optional) Enter a specific protocol name.

 

Verifying Unknown and Unclassified Traffic Management

To verify the management of unknown and unclassified traffic, perform the following steps.

SUMMARY STEPS

1. show ip nbar protocol-id unknown

2. show ip nbar link-age unknown

3. show ip nbar protocol-attribute unknown


DETAILED STEPS
  Command or Action Purpose
Step 1 show ip nbar protocol-id unknown


Example:
Device# show ip nbar protocol-id unknown

Protocol Name             id            type
----------------------------------------------
unknown                  1             L7 STANDARD
 

(Optional) Displays protocol classification ID for unknown and unclassified traffic.

 
Step 2 show ip nbar link-age unknown


Example:
Device# show ip nbar link-age unknown

Protocol                  Link Age (seconds)
unknown                      60
 

(Optional) Displays the protocol link age for unknown and unclassified traffic.

 
Step 3 show ip nbar protocol-attribute unknown


Example:
Device# show ip nbar protocol-attribute unknown

           Protocol Name : unknown
               encrypted : encrypted-no
                  tunnel : tunnel-no
                category : other
            sub-category : other
       application-group : other
          p2p-technology : p2p-tech-no
 

(Optional) Displays list of configured attributes for unknown and unclassified traffic.

 

Configuration Examples for Configuring DSCP-Based Layer 3 Custom Applications

Example Configuring a Traffic Class

In the following example, a class called cmap1 has been configured. All traffic that matches the citrix protocol will be placed in the cmap1 class.

Device> enable
Device# configure terminal
Device(config)# class-map cmap1
Device(config-cmap)# match protocol citrix
Device(config-cmap)# end

Example Configuring a Traffic Policy

In the following example, a traffic policy (policy map) called policy1 has been configured. Policy1 contains a class called class1, within which CBWFQ has been enabled.

Device> enable
Device# configure terminal
Device(config)# policy-map policy1
Device(config-pmap)# class class1
Device(config-pmap-c)# bandwidth percent 50
Device(config-pmap-c)# end

Note


In the above example, the bandwidth command is used to enable Class-Based Weighted Fair Queuing (CBWFQ). CBWFQ is only an example of one QoS feature that can be applied in a policy map. Use the appropriate command for the QoS feature that you want to use. As of Cisco IOS Release 12.2(18)ZY, CBWFQ is not supported on the Catalyst 6500 series switch that is equipped with a Supervisor 32/PISA.


Example Attaching a Traffic Policy to an Interface or Subinterface

In the following example, the traffic policy (policy map) called policy1 has been attached to Ethernet interface 2/4 in the input direction of the interface.

Device> enable
Device# configure terminal
Device(config)# interface ethernet 2/4 
Device(config-if)# service-policy input policy1
Device(config-if)# end

Example Verifying the NBAR Protocol-to-Port Mappings

The following is sample output of the show ip nbar port-map command. This command displays the current protocol-to-port mappings in use by NBAR. Use the display to verify that these mappings are correct.

Device# show ip nbar port-map
port-map bgp      udp 179 
port-map bgp      tcp 179 
port-map cuseeme  udp 7648 7649 
port-map cuseeme  tcp 7648 7649 
port-map dhcp     udp 67 68 
port-map dhcp     tcp 67 68 

If the ip nbar port-map command has been used, the show ip nbar port-map command displays the ports assigned to the protocol.

If the no ip nbar port-mapcommand has been used, the show ip nbar port-map command displays the default ports. To limit the display to a specific protocol, use the protocol-name argument of the show ip nbar port-map command.

Example: L3 Custom any IP Port

Device> enable
Device# configuration terminal
Device (config)# ip nbar custom mycustom transport udp-tcp
Device(config-custom)# dscp ef
Device (config-custom)# exit

Where to Go Next

To add application recognition modules (also known as Packet Description Language Modules or PDLMs) to your network, see the "Adding Application Recognition Modules" module.

To classify network traffic on the basis of a custom protocol, see the "Creating a Custom Protocol" module.

Additional References

The following sections provide references related to configuring NBAR using the MQC.

Related Documents

Related Topic

Document Title

QoS commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples

Cisco IOS Quality of Service Solutions Command Reference

QoS features and functionality on the Catalyst 6500 series switch

"Configuring PFC QoS" chapter of the Catalyst Supervisor Engine 32 PISA Cisco IOS Software Configuration Guide , Release 12.2ZY

MQC, traffic policies (policy maps), and traffic classes

"Applying QoS Features Using the MQC" module

CBWFQ

"Configuring Weighted Fair Queueing" module

Concepts and information about NBAR

"Classifying Network Traffic Using NBAR" module

Information about enabling Protocol Discovery

"Enabling Protocol Discovery" module

Information about adding application recognition modules (also known as PDLMs)

"Adding Application Recognition Modules" module

Creating a custom protocol

"Creating a Custom Protocol" module

Technical Assistance

Description

Link

The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies.

To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.

Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.

http:/​/​www.cisco.com/​techsupport

Feature Information for Configuring NBAR Using the MQC

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/​go/​cfn. An account on Cisco.com is not required.
Table 2 Feature Information for Configuring NBAR Using the MQC

Feature Name

Releases

Feature Information

NBAR MQC Support for Pre-resolved and Unknown Applications

IOS Release 15.5(1)T

IOS XE Release 3.14S

The NBAR MQC Support for Pre-resolved and Unknown Applications feature provides support for matching all unknown and unclassified traffic using MQC.

The following commands were modified: class-map, match protocol

QoS: DirectConnect PDLM

12.4(4)T

Provides support for the DirectConnect protocol and Packet Description Language Module (PDLM). The DirectConnect protocol can now be recognized when using the MQC to classify traffic.

The following sections provide information about the QoS: DirectConnect PDLM feature:

QoS: Skype Classification

12.4(4)T

Provides support for the Skype protocol. The Skype protocol can now be recognized when using the MQC to classify traffic.

Note   

Cisco currently supports Skype Version 1 only.

The following sections provide information about the QoS: Skype Classification feature:

NBAR--BitTorrent PDLM

12.4(2)T

Provides support for the BitTorrent PDLM and protocol. The BitTorrent protocol can now be recognized when using the MQC to classify traffic.

The following sections provide information about the NBAR-BitTorrent PDLM feature:

NBAR--Citrix ICA Published Applications

12.4(2)T

Enables NBAR to classify traffic on the basis of the Citrix Independent Computing Architecture (ICA) published application name and tag number.

The following sections provide information about the NBAR-Citrix ICA Published Applications feature:

NBAR--Multiple Matches Per Port

12.4(2)T

Provides the ability for NBAR to distinguish between values of an attribute within the traffic stream of a particular application on a TCP or UDP port.

The following sections provide information about the NBAR-Multiple Matches Per Port feature:

NBAR Extended Inspection for HTTP Traffic

12.3(4)T

Allows NBAR to scan TCP ports that are not well known and identify HTTP traffic that traverses these ports.

The following sections provide information about the NBAR Extended Inspection for HTTP Traffic feature:

NBAR Real-Time Transport Protocol Payload Classification

12.2(15)T

Enables stateful identification of real-time audio and video traffic.

The following section provides information about the NBAR Real-Time Transport Protocol Payload Classification feature:

NBAR--Network-Based Application Recognition

12.2(18)ZYA

Integrates NBAR and Firewall Service Module (FWSM) functionality on the Catalyst 6500 series switch that is equipped with a Supervisor 32/programmable intelligent services accelerator (PISA). Additional protocols are now recognized by NBAR.

The following sections provide information about the NBAR feature:

The following command was modified: match protocol (NBAR).

NBAR--Network-Based Application Recognition (Hardware Accelerated NBAR)

12.2(18)ZY

Enables NBAR functionality on the Catalyst 6500 series switch that is equipped with a Supervisor 32/programmable intelligent services accelerator (PISA).

The following section provides information about the NBAR--Network-Based Application Recognition (Hardware Accelerated NBAR) feature: