IP Tunnel MIBs

First Published: October 24,2007
Last Updated: September 10, 2010

This module contains information about MIBs used with interfaces and hardware components. The IP Tunnel MIB feature provides a generic MIB for managing all IPv4- and IPv6-related tunnels, as outlined in RFC 4087, IP Tunnel MIB. Tunneling provides a way to encapsulate arbitrary packets inside a transport protocol. A number of tunneling mechanism s specified by Internet Engineering Task Force (IETF) are implemented by Cisco for both IPv4 and IPv6 environments. Various MIBs are available for managing tunnels.

Finding Feature Information

Your Cisco IOS software release may not support all of the features documented in this document. 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 the Tunnel MIB" section.

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://tools.cisco.com/ITDIT/CFN/jsp/index.jsp. An account on Cisco.com is not required.

Contents

•Prerequisites for the IP Tunnel MIB

•Restrictions for the IP Tunnel MIB

•Information About the IP Tunnel MIB

•How to Configure SNMP and Use the IP Tunnel MIB

•Additional References

•Feature Information for the Tunnel MIB

Prerequisites for the IP Tunnel MIB

Configure Simple Network Management Protocol (SNMP) on the router on which the IP Tunnel MIB feature is to be used. See the "Configuring the Router to Use SNMP" section for more information. For more information on configuring an SNMP server, see the "Configuring SNMP Support" chapter of the Cisco IOS Network Management Configuration Guide.

Restrictions for the IP Tunnel MIB

The IP Tunnel MIB feature supports only tunnels that can be created using the interface tunnel command. The IP Tunnel MIB feature does not support Layer 2 Tunnel Protocol (L2TP), Point-to-Point Tunneling Protocol (PPTP), or Multiprotocol Label Switching (MPLS) tunnels.

Information About the IP Tunnel MIB

•Benefits of the IP Tunnel MIB

•MIB Objects Supported by the IP Tunnel MIB

Benefits of the IP Tunnel MIB

Improved Quality of Networks

Better IP tunnel instrumentation leads to an improvement in the quality of networks and better service delivery. A better quality network  allows service providers to deliver a more reliable service.

Increased Reliability

The IP Tunnel MIB allows users of network management systems to set inventory and receive notification about their IP tunnel activity.

The IP Tunnel MIB supports both IPv4 and IPv6 network layers as defined in RFC 3291, and is used to manage IP tunnels implemented in the Cisco IOS software.

The IP Tunnel MIB supports all tunnel types, as well as tunnel creation and destruction capability.

Interoperability with Devices Other Than Cisco Devices

The IP Tunnel MIB works with key network management systems, including those of third-party vendors.

MIB Objects Supported by the IP Tunnel MIB

The following MIB objects are supported by the IP Tunnel MIB feature. For details regarding use of MIB objects, see RFC 4087, IP Tunnel MIB.

Table 1

MIB Object
Description

tunnelIfEntry

Contains information on a particular configured tunnel. You can use the interface tunnel command to set a value for this object.

tunnelIfEncapsMethod

The encapsulation method used by the tunnel. You can use the tunnel mode command to set a value for this object.

tunnelIfHopLimit

Defines the IPv4 time to live (TTL) or IPv6 hop limit to use in the outer IP header. You can use the tunnel ttl command to set a value for this object.

tunnelIfSecurity

Used by the tunnel to secure the outer IP header. The value ipsec indicates that IPsec is used between the tunnel endpoints for authentication or encryption, or both.

tunnelIfTOS

Used by the tunnel to set the high 6 bits (the differentiated services codepoint) of the IPv4 type of service (ToS) or IPv6 traffic class in the outer IP header. You can use the tunnel tos command to set a value for this object.

tunnelIfFlowLabel

Used to set the IPv6 Flow Label value. This object is supported for tunnels over IPv6. The default value for this object is 0.

tunnelIfAddressType

Shows the type of address in the corresponding tunelIfLocalInetAddress and tunnelIfRemoteInetAddress objects. This object cannot be configured individually through the command-line interface (CLI).

tunnelIfLocalInetAddress

The address of the local endpoint of the tunnel (that is, the source address used in the outer IP header). If the address is unknown, the value is 0.0.0.0 for IPv4 or :: for IPv6. The address type of this object is given by tunnelIfAddressType. You can use the tunnel source command to set a value for this object.

tunnelIfRemoteInetAddress

The address of the remote endpoint of the tunnel (that is, the destination address used in the outer IP header). If the address is unknown or the tunnel is not a point-to-point link (for example, a 6-to-4 tunnel), the value is 0.0.0.0 for tunnels over IPv4 or :: for tunnels over IPv6. The address type of this object is given by tunnelIfAddressType. You can use the tunnel destination command to set a value for this object.

tunnelIfEncapsLimit

Shows the maximum number of additional encapsulations permitted for packets undergoing encapsulation at this node. A value of -1 indicates that no limit is present (except as result of packet size).

tunnelInetConfigEntry

Contains information on a particular configured tunnel. There will be only one entry for multipoint tunnels and for tunnels that have the remote inet address 0.0.0.0 for IPv4 or :: for IPv6. Only generic routing encapsulation (GRE)/IP and GRE/IPv6 tunnels are created through the MIB.

tunnelInetConfigIfIndex

Shows the value of ifIndex corresponding to the tunnel interface. A value of 0 is not legal in the active state and means that the interface index has not yet been assigned.

tunnelInetConfigStatus

Used to create or delete table entries in the MIB table. You can use the interface tunnel to set a value for this object.

tunnelInetConfigStorageType

Indicates the storage type. Only a nonvolatile storage value is supported.


Objects Supported by the IP Tunnel MIB

How to Configure SNMP and Use the IP Tunnel MIB

•Configuring the Router to Use SNMP (required)

Configuring the Router to Use SNMP

Note Some of the tasks in this section include examples of the SNMP CLI syntax used to set configuration parameters on the router and to read values from MIB objects on the router. These SNMP CLI syntax examples are taken from a Linux workstation using public domain SNMP tools. The SNMP CLI syntax for your workstation might be different. See the documentation that was provided with your SNMP tools for the correct syntax for your network management workstation.

Before you can use the IP Tunnel MIB feature, you must first configure the router to support SNMP. Perform this task to enable SNMP on the router.

SUMMARY STEPS

1. enable

2. configure terminal

3. snmp-server community string1 ro

4. snmp-server community string2 rw

5. end

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 community string1 ro

Example:

Router(config)# snmp-server community public ro

Sets up the community access string to permit access to SNMP.

•The string1 argument is a community string that consists of from 1 to 32 alphanumeric characters and functions much like a password, permitting access to the SNMP protocol. Blank spaces are not permitted in the community string.

•The ro keyword specifies read-only access. SNMP management stations using this string can retrieve MIB objects.

Note The SNMP community read-only (RO) string for the examples is public. You should use a more complex string for this value in your configuration.

Step 4 

snmp-server community string2 rw

Example:

Router(config)# snmp-server community private rw

Sets up the community access string to permit access to SNMP.

•The string2 argument is a community string that consists of from 1 to 32 alphanumeric characters and functions much like a password, permitting access to the SNMP protocol. Blank spaces are not permitted in the community string.

•The rw keyword specifies read-write access. SNMP management stations using this string can retrieve and modify MIB objects.

Note The SNMP community read-write (RW) string for the examples is private. You should use a more complex string for this value in your configuration.

Step 5 

end

Example:

Router(config)# end

Exits the current configuration mode and returns to privileged EXEC mode.

What to Do Next

To implement the IP Tunnel MIB, you must configure a tunnel. For information on configuring tunnels, see the "Implementing Tunnels" chapter in the Cisco IOS Interface and Hardware Component Configuration Guide.

To debug or troubleshoot any issues related to configuring the IP Tunnel MIB through SNMP, use the debug snmp tunnel-mib command. For information on this command see Cisco IOS Interface and Hardware Component Command Reference.

Additional References

Related Documents

Related Topic
Document Title

SNMP commands, complete command syntax, command reference, command history, defaults, defaults, usage guidelines, and examples

Cisco IOS Network Management Command Reference

Configuring SNMP Support

Cisco IOS Network Management Configuration Guide

Implementing tunnels

Cisco IOS Interface and Hardware Component Configuration Guide


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

IP Tunnel MIB

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 4087

IP Tunnel MIB


Technical Assistance

Description
Link

The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password.

http://www.cisco.com/cisco/web/support/index.html


Feature Information for the Tunnel MIB

Table 2 lists the release history for this feature.

Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.

Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://tools.cisco.com/ITDIT/CFN/jsp/index.jsp. An account on Cisco.com is not required.

Note Table 2 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 2 Feature Information for the IP Tunnel MIB

Feature Name
Releases
Feature Information

IP Tunnel MIB

12.2(33)SRB
12.2(1st)SY
12.2(44)SG
12.2(33)SRD
15.0(1)M
Cisco IOS XE 3.1.0SG

The IP Tunnel MIB provides a generic MIB for managing all IPv4- and IPv6-related tunnels, as outlined in RFC 4087 IP Tunnel MIB.


Cisco and the Cisco Logo are trademarks of Cisco Systems, Inc. and/or its affiliates in the U.S. and other countries. A listing of Cisco's trademarks can be found at www.cisco.com/go/trademarks. Third party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1005R)

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

© 2007-2010 Cisco Systems, Inc. All rights reserved.