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SNMP--IP Precedence and DSCP Support

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SNMP—IP Precedence and DSCP Support

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

snmp-server ip dscp

snmp-server ip precedence


SNMP—IP Precedence and DSCP Support


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).

Feature History for the SNMP—IP Precedence and DSCP Support Feature

Release
Modification

12.0(26)S

This feature was introduced.


Finding Support Information for Platforms and Cisco IOS Software Images

Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.

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

Configuration Examples for SNMP—IP Precedence and DSCP Support

Additional References

Command Reference

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

Configuring IP Precedence or IP DSCP for SNMP Traffic

To configure IP Precedence or IP DSCP for SNMP traffic, perform the following steps:

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

Router(config)# snmp-server ip dscp 45

Configures an IP Precedence value for SNMP traffic.

or

Configures an IP DSCP value 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

For additional information related to SNMP—IP Precedence and DSCP Support, refer to the following references:

Related Documents

Related Topic
Document Title

QoS IP procedure

Cisco IOS Quality of Service Configuration Guide, Release 12.0

SNMP

Cisco IOS Configuration Fundamentals Configuration Guide, Release 12.0

QoS policies

Cisco IOS Configuration Fundamentals Configuration Guide, Release 12.0


Standards

Standards 1
Title

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

1 Not all supported standards are listed.


MIBs

MIBs 1
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

1 Not all supported MIBs are listed.


RFCs

RFCs 1
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

1 Not all supported RFCs are listed.


Technical Assistance

Description
Link

Technical Assistance Center (TAC) home page, containing 30,000 pages of searchable technical content, including links to products, technologies, solutions, technical tips, and tools. Registered Cisco.com users can log in from this page to access even more content.

http://www.cisco.com/public/support/tac/home.shtml


Command Reference

This section documents new or modified commands. All other commands used with this feature are documented in the Cisco IOS Release 12.0 command reference publications.

snmp-server ip dscp

snmp-server ip precedence

snmp-server ip dscp

To set the IP Differentiated Services Code Point (DSCP) value for Simple Network Management Protocol (SNMP) traffic, use the snmp-server ip dscp command in global configuration mode. To disable the configured value, use the no form of this command.

snmp-server ip dscp value

no snmp-server ip dscp

Syntax Description

value

The IP DSCP value to apply to SNMP traffic. Valid values for IP DSCP are 0 through 63.


Defaults

The IP DSCP default value for SNMP traffic is 0.

Command Modes

Global configuration

Command History

Release
Modification

12.0(26)S

This command was introduced.


Usage Guidelines

Use this command to specify an IP DSCP value to give SNMP traffic higher or lower priority in your network.

Examples

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

Router(config)# snmp-server ip dscp 45

Related Commands

Command
Description

snmp-server ip precedence

Configures the IP Precedence value.


snmp-server ip precedence

To set the IP Precedence value for Simple Network Management Protocol (SNMP) traffic, use the snmp-server ip precedence command in global configuration mode. To disable the configured value, use the no form of this command.

snmp-server ip precedence value

no snmp-server ip precedence

Syntax Description

value

The IP Precedence value to apply to SNMP traffic. Valid values for IP Precedence are 0 through 7.


Defaults

The IP Precedence default value for SNMP traffic is 0.

Command Modes

Global configuration

Command History

Release
Modification

12.0(26)S

This command was introduced.


Usage Guidelines

Use this command to specify an IP Precedence value to give SNMP traffic higher or lower priority in your network.

Examples

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

Router(config)# snmp-server ip precedence 7

Related Commands

Command
Description

snmp-server ip dscp

Configures the IP DSCP code point value.