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SNMP-IP Precedence and DSCP Support

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Table Of Contents

SNMP—IP Precedence and DSCP Support

Contents

Prerequisites for SNMP—IP Precedence and DSCP Support

Information About SNMP—IP Precedence and DSCP Support

How to Configure SNMP—IP Precedence and DSCP Support

Configuring IP Precedence or IP DSCP for SNMP Traffic

Configuration Examples for SNMP—IP Precedence and DSCP Support

Setting an IP Precedence Value for SNMP Traffic: Example

Setting an IP DSCP Value for SNMP Traffic: Example

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Command Reference

Feature Information for SNMP—IP Precedence and DSCP Support


SNMP—IP Precedence and DSCP Support

First Published: April 21, 2006
Last Updated: July 9, 2008

The SNMP—IP Precedence and DSCP Support feature provides the ability to set the Quality of Service (QoS) for locally generated Simple Network Management Protocol (SNMP) traffic. You classify SNMP traffic based on either the IP Precedence or IP Differentiated Services Code Point (DSCP) value. The IP Precedence or IP DSCP code point value is used to determine how packets are handled in Weighted Random Early Detection (WRED).

Finding Feature Information in This Module

Your Cisco IOS software release may not support all of the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To reach links to specific feature documentation in this module and to see a list of the releases in which each feature is supported, use the "Feature Information for SNMP—IP Precedence and DSCP Support" section.

Finding Support Information for Platforms and Cisco IOS and Catalyst OS Software Images

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

Contents

•Prerequisites for SNMP—IP Precedence and DSCP Support, page 2

•Information About SNMP—IP Precedence and DSCP Support

•How to Configure SNMP—IP Precedence and DSCP Support

•Configuration Examples for SNMP—IP Precedence and DSCP Support

•Additional References

•Command Reference

•Feature Information for SNMP—IP Precedence and DSCP Support

Prerequisites for SNMP—IP Precedence and DSCP Support

The tasks for this feature assume that SNMP is configured.

Information About SNMP—IP Precedence and DSCP Support

The SNMP—IP Precedence and DSCP Support feature delivers QoS specifically for SNMP traffic. This feature allows you to change the priority setting so that SNMP traffic generated in a router is assigned a specific QoS class. The IP Precedence or IP DSCP code point value is used to determine how packets are handled in WRED.

After IP Precedence or DSCP is set for the SNMP traffic generated in a router, different QoS classes cannot be assigned to different types of SNMP traffic in that router.

The IP Precedence value is the first three bits in the Type of Service (ToS) byte of an IP header. The IP DSCP code point value is the first six bits of the Differentiate Services (DiffServ Field) byte. You can configure up to eight different IP Precedence markings or 64 different IP DSCP markings.

How to Configure SNMP—IP Precedence and DSCP Support

To configure the SNMP—IP Precedence and DSCP Support feature, perform the following task:

Configuring IP Precedence or IP DSCP for SNMP Traffic, page 2 (required)

Configuring IP Precedence or IP DSCP for SNMP Traffic

Perform this task to configure IP Precedence or IP DSCP for SNMP traffic.

SUMMARY STEPS

1. enable

2. configure terminal

3. snmp-server ip precedence value
or
snmp-server ip dscp value

4. exit

5. copy running-config startup-config

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

snmp-server ip precedence value

or

snmp-server ip dscp value

Example:

Router(config)# snmp-server ip precedence 7

or

Example:

Router(config)# snmp-server ip dscp 45

Configures an IP Precedence value for SNMP traffic.

or

Configures an IP DSCP value for SNMP traffic.

Step 4 

exit

Example:

Router(config)# exit

Exits global configuration mode, and returns the router to privileged EXEC mode.

Step 5 

copy running-config startup-config

Example:

Router# copy running-config startup-config

Save the configuration file to your startup configuration.

Configuration Examples for SNMP—IP Precedence and DSCP Support

This section contains the following configuration examples:

•Setting an IP Precedence Value for SNMP Traffic: Example

•Setting an IP DSCP Value for SNMP Traffic: Example

Setting an IP Precedence Value for SNMP Traffic: Example

The following example shows how to set the SNMP IP Precedence value to 7:

Router> enable 

Router# configure terminal

Router(config)# snmp-server ip precedence 7

Router(config)# exit

Router# copy running-config startup-config

Setting an IP DSCP Value for SNMP Traffic: Example

The following example shows how to set the IP DSCP value of SNMP traffic to 45: 

Router> enable

Router# configure terminal

Router(config)# snmp-server ip dscp 45 

Router(config)# exit

Router# copy running-config startup-config

Additional References

The following sections provide references related to the SNMP—IP Precedence and DSCP Support feature.

Related Documents

Related Topic
Document Title

QoS IP Configuration Tasks

Cisco IOS Quality of Service Configuration Guide, Release 12.4

SNMP

Cisco IOS Configuration Fundamentals Configuration Guide, Release 12.0

QoS policies

Cisco IOS Configuration Fundamentals Configuration Guide, Release 12.0


Standards

Standard
Title

No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.

—


MIBs

MIB
MIBs Link

No new or modified MIBs are supported by this feature, and support for existing MIBs has not been modified by this feature.

To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs


RFCs

RFC
Title

RFC 2474

Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers

RFC 2475

An Architecture for Differentiated Services

RFC 2597

Assured Forwarding PHB Group

RFC 2598

An Expedited Forwarding PHB


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


Command Reference

The following commands are introduced or modified in the feature or features documented in this module. For information about these commands, see the Cisco IOS Network Management Command Reference at http://www.cisco.com/en/US/docs/ios/netmgmt/command/reference/nm_book.html. For information about all Cisco IOS commands, use the Command Lookup Tool at http://tools.cisco.com/Support/CLILookup or the Cisco IOS Master Command List, All Releases, at http://www.cisco.com/en/US/docs/ios/mcl/allreleasemcl/all_book.html.

•snmp-server ip dscp

•snmp-server ip precedence

Feature Information for SNMP—IP Precedence and DSCP Support

Table 1 lists the release history for this feature.

Table 1 lists the features in this module and provides links to specific configuration information. Only features that were introduced or modified in Cisco IOS Release 12.0(26)S or a later release appear in the table.

For information on a feature in this technology that is not documented here, see the other available documentation for your Cisco IOS release.

Note Table 1 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.

Table 1 Feature Information for SNMP—IP Precedence and DSCP Support 

Feature Name
Releases
Feature Information

SNMP—IP Precedence and DSCP Support

12.0(26)S

12.2(7)S

12.4(21)M

The SNMP—IP Precedence and DSCP Support feature provides the ability to set the Quality of Service (QoS) for locally generated Simple Network Management Protocol (SNMP) traffic.

The following commands were introduced or modified: snmp-server ip precedence, snmp-server ip dscp.


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Any Internet Protocol (IP) addresses used in this document are not intended to be actual addresses. Any examples, command display output, and figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses in illustrative content is unintentional and coincidental.

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