OSPF: SNMP ifIndex Value for Interface ID in OSPFv2 and OSPFv3 Data Fields

First Published: February 27, 2006
Last Updated: Feb 15, 2010

This feature allows you to configure the interface ID value Open Shortest Path First version 2 (OSPFv2) and Open Shortest Path First version 3 (OSPFv3) data fields. You can choose to use either the current interface number or the Simple Network Management Protocol (SNMP) MIB-II interface index (ifIndex) value for the interface ID. The advantage to using the SNMP MIB-II ifIndex value is that this number corresponds to the number that the user will see reported by SNMP.

Finding Feature Information

For the latest feature information and caveats, see 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 for OSPF: SNMP ifIndex Value for Interface ID in OSPFv2 and OSPFv3 Data Fields" section.

Use Cisco Feature Navigator to find information about platform support and Cisco IOS XE 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 Using the SNMP ifIndex Value for Interface ID in OSPFv2 and OSPFv3 Data Fields

•Information About the SNMP ifIndex Value for Interface ID in OSPFv2 and OSPFv3 Data Fields

•How to Configure the SNMP ifIndex Value for Interface ID in OSPFv2 and OSPFv3 Data Fields

•Configuration Examples for Using the SNMP ifIndex Value for Interface ID in OSPFv2 and OSPFv3 Data Fields

•Additional References

•Feature Information for OSPF: SNMP ifIndex Value for Interface ID in OSPFv2 and OSPFv3 Data Fields

Prerequisites for Using the SNMP ifIndex Value for Interface ID in OSPFv2 and OSPFv3 Data Fields

Before you can use the SNMP ifIndex value for interface identification, OSPF must be configured on the router.

Information About the SNMP ifIndex Value for Interface ID in OSPFv2 and OSPFv3 Data Fields

Before choosing to switch from the current interface numbers to the SNMP MIB-II interface ID numbers, you should understand the following concepts:

•Benefits of Choosing to Identify Interfaces by the SNMP MIB-II ifIndex Value

•How OSPFv2 and OSPFv3 Use the SNMP MIB-II ifIndex Value

Benefits of Choosing to Identify Interfaces by the SNMP MIB-II ifIndex Value

If you use SNMP for your OSPF network, configuring the OSPF: SNMP ifIndex Value for Interface ID in OSPFv2 and OSPFv3 Data Fields feature can be beneficial for the following reasons:

•Using the SNMP MIB-II ifIndex identification numbers to identify OSPF interfaces makes it easier for network administrators to identify interfaces because the numbers will correspond to the numbers that they will see reported by SNMP.

•In the link-state advertisements (LSAs), the value used in fields that have the interface ID will be the same as the value that is reported by SNMP.

•In the output from the show ipv6 ospf interface command, the interface ID number will have the same value that is reported by SNMP.

•Using the SNMP MIB-II IfIndex is also suggested, but not required, by the OSPF RFC 2328 for OSPFv2 and the RFC 2740 for OSPFv3.

How OSPFv2 and OSPFv3 Use the SNMP MIB-II ifIndex Value

The user chooses for OSPF interfaces to use the SNMP MIB-II ifIndex number by entering the interface-id snmp-if-index command for a specific OSPF process. If an interface under the specific OSPF process does not have an SNMP ifIndex number, OSPF will not be enabled on that interface.

For OSPFv2, the ifIndex number is used for the Link Data field in the Router LSA for unnumbered point-to-point interfaces and sham links. When the interface-id snmp-if-index command is entered, the affected LSAs will immediately be reoriginated.

For OSPFv3, the ifIndex number is used for the interface ID in router LSAs, as the LSID in Network and Link LSAs, and also as the interface ID in Hello packets. Intra-Area-Prefix LSAs that reference Network LSAs have the Network LSAs LSID in the Referenced LSID field, so they will also be updated when the interface-id snmp-if-index command is entered. The old Network, Link, and Intra-Area-Prefix LSAs that are associated with a Network LSA will be flushed.

For both OSPFv2 and OSPFv3, adjacencies are not flapped, except for affected OSPFv3 demand circuits (including virtual links) with full adjacencies.

For both OSPFv2 and OSPFv3, if an interface does not have an SNMP ifIndex number and an interface ID is needed (for OSPFv2 this applies only to unnumbered interfaces and sham links), an error message will be generated and the interface will be disabled. The interface will be reenabled if the no interface-id snmp-if-index command is entered.

How to Configure the SNMP ifIndex Value for Interface ID in OSPFv2 and OSPFv3 Data Fields

Configuring OSPF interfaces to use SNMP MIB-II ifIndex Numbers and Verifying the Configuration

SUMMARY STEPS

1. enable

2. configure terminal

3. router ospf process-id [vrf vpn-name]

or

ipv6 router ospf process-id

4. interface-id snmp-if-index

5. end

6. show snmp mib ifmib ifindex [type number] [detail][free-list]

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 

router ospf process-id [vrf vpn-name]

or

ipv6 router ospf process-id

Example:

Router(config)# router ospf 4

or

Router(config)# ipv6 router ospf 4

Configures an OSPFv2 routing process and enters router configuration mode.

Configures an OSPFv3 routing process and enters router configuration mode.

Note If you configure an OSPFv3 routing process, that uses IPv6, you must have already enabled IPv6.

Step 4 

interface-id snmp-if-index

Example:

Router(config-router)# interface-id snmp-if-index

Configures OSPF interfaces with the SNMP interface index identification numbers (ifIndex values).

Step 5 

end

Example:

Router(config-router)# end

Returns to privileged EXEC mode.

Repeat this task for each OSPF process for which you want the interfaces to use the SNMP MIB-II ifIndex numbers.

Step 6 

show snmp mib ifmib ifindex [type number] [detail][free-list]

Example:

Router# show snmp mib ifmib ifindex  GigabitEtherent0/0/0

Displays SNMP interface index identification numbers (ifIndex values) for all the system interfaces or the specified system interface.

Configuration Examples for Using the SNMP ifIndex Value for Interface ID in OSPFv2 and OSPFv3 Data Fields

This section contains the following examples:

•Example: Configuring the SNMP ifIndex Value for Interface ID for OSPFv2

•Example: Configuring the SNMP ifIndex Value for Interface ID for OSPFv3

Example: Configuring the SNMP ifIndex Value for Interface ID for OSPFv2

The following example configures the OSPF interfaces to use the SNMP ifIndex values for the interfaces IDs. The show snmp mib ifmib ifindex command confirms that the SNMP MIB-II ifIndex values are used for the interface ID values in the OSPFv2 data fields. 

Router# configure terminal

Enter configuration commands, one per line.  End with CNTL/Z.

Router(config)# router ospf 1

Router(config-router)# interface-id snmp-if-index

Router(config-router)# ^Z

Router# show ip ospf 1 1 data router self

OSPF Router with ID (172.16.0.1) (Process ID 1)

Router Link States (Area 1) 


LS age: 6

Options: (No TOS-capability, DC) 
LS Type: Router Links 
Link State ID: 172.16.0.1 
Advertising Router: 172.16.0.1 
LS Seq Number: 80000007 
Checksum: 0x63AF 
Length: 48 
Area Border Router 
Number of Links: 2


Link connected to: another Router (point-to-point)

(Link ID) Neighboring Router ID: 172.17.0.1

(Link Data) Router Interface address: 0.0.0.53

Number of TOS metrics: 0

TOS 0 Metrics: 64


Link connected to: a Stub Network

(Link ID) Network/subnet number: 192.168.0.11

(Link Data) Network Mask: 255.255.255.255

Number of TOS metrics: 0

TOS 0 Metrics: 1 


Router# show snmp mib ifmib ifindex serial 13/0 


Serial13/0: Ifindex = 53

Example: Configuring the SNMP ifIndex Value for Interface ID for OSPFv3

The following example configures the OSPFv3 interfaces to use the SNMP ifIndex values for the interface IDs: 

Router# configure terminal

Enter configuration commands, one per line.  End with CNTL/Z.

Router(config)# ipv6 router ospf 1

Router(config-router)# interface-id snmp-if-index

The output from the show snmp mib ifmib ifindex command confirms that the SNMP MIB-II ifIndex values are being used for the interface ID values in the OSPFv2 data fields: 

Router# show snmp mib ifmib ifindex GigabitEthernet 0/0/0


0/0/0: Ifindex = 5


Router# show ipv6 ospf interface


OSPF_VL0 is up, line protocol is up 

  Interface ID 71

  Area 0, Process ID 1, Instance ID 0, Router ID 172.16.0.1

  Network Type VIRTUAL_LINK, Cost: 10

  Configured as demand circuit.

  Run as demand circuit.

  DoNotAge LSA allowed.

  Transmit Delay is 1 sec, State POINT_TO_POINT,

  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5

    Hello due in 00:00:02

  Index 1/2/3, flood queue length 0

  Next 0x0(0)/0x0(0)/0x0(0)

  Last flood scan length is 1, maximum is 1

  Last flood scan time is 0 msec, maximum is 0 msec

  Neighbor Count is 1, Adjacent neighbor count is 1

    Adjacent with neighbor 10.0.0.1  (Hello suppressed)

  Suppress hello for 1 neighbor(s)

GigabitEthernet is up, line protocol is up 

  Link Local Address FE80::A8BB:CCFF:FE00:6F02, Interface ID 10

  Area 0, Process ID 1, Instance ID 0, Router ID 172.16.0.1

  Network Type BROADCAST, Cost: 10

  Transmit Delay is 1 sec, State DR, Priority 1 

  Designated Router (ID) 172.16.0.1, local address FE80::A8BB:CCFF:FE00:6F02

  No backup designated router on this network

  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5

    Hello due in 00:00:06

  Index 1/1/2, flood queue length 0

  Next 0x0(0)/0x0(0)/0x0(0)

  Last flood scan length is 0, maximum is 0

  Last flood scan time is 0 msec, maximum is 0 msec

  Neighbor Count is 0, Adjacent neighbor count is 0 

  Suppress hello for 0 neighbor(s)

GigabitEthernet is up, line protocol is up 

  Link Local Address FE80::A8BB:CCFF:FE00:6F01, Interface ID 6

  Area 1, Process ID 1, Instance ID 2, Router ID 172.16.0.1

  Network Type BROADCAST, Cost: 10

  Transmit Delay is 1 sec, State DR, Priority 1 

  Designated Router (ID) 172.16.0.1, local address FE80::A8BB:CCFF:FE00:6F01

  Backup Designated router (ID) 10.0.0.1, local address FE80::A8BB:CCFF:FE00:6E01

  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5

    Hello due in 00:00:06

  Index 1/1/1, flood queue length 0

  Next 0x0(0)/0x0(0)/0x0(0)

  Last flood scan length is 1, maximum is 2

  Last flood scan time is 0 msec, maximum is 0 msec

  Neighbor Count is 1, Adjacent neighbor count is 1 

    Adjacent with neighbor 10.0.0.1  (Backup Designated Router)

  Suppress hello for 0 neighbor(s)


Router# show ipv6 ospf database network adv-router 172.16.0.1


OSPFv3 Router with ID (172.16.0.1) (Process ID 1)

Net Link States (Area 1)


  LS age: 144

  Options: (V6-Bit E-Bit R-bit DC-Bit)

  LS Type: Network Links

  Link State ID: 6 (Interface ID of Designated Router)

  Advertising Router: 172.16.0.1

  LS Seq Number: 80000001

  Checksum: 0x1FC0

  Length: 32

        Attached Router: 172.16.0.1

        Attached Router: 10.0.0.1


Router# show ipv6 ospf database prefix adv-router 172.16.0.1


OSPFv3 Router with ID (172.16.0.1) (Process ID 1)

Intra Area Prefix Link States (Area 0)


Routing Bit Set on this LSA

LS age: 196

LS Type: Intra-Area-Prefix-LSA

Link State ID: 0

Advertising Router: 172.16.0.1

LS Seq Number: 80000001

Checksum: 0x6F11

Length: 44

  Referenced LSA Type: 2001

  Referenced Link State ID: 0

  Referenced Advertising Router: 172.16.0.1

  Number of Prefixes: 1

  Prefix Address: 2002:0:2::

  Prefix Length: 64, Options: None, Metric: 10


Intra Area Prefix Link States (Area 1)


  Routing Bit Set on this LSA

  LS age: 161

  LS Type: Intra-Area-Prefix-LSA

  Link State ID: 0

  Advertising Router: 172.16.0.1

  LS Seq Number: 80000001

  Checksum: 0xB6E7

  Length: 52

  Referenced LSA Type: 2001

  Referenced Link State ID: 0

  Referenced Advertising Router: 172.16.0.1

  Number of Prefixes: 1

  Prefix Address: 2002:0:2:0:A8BB:CCFF:FE00:6F02

  Prefix Length: 128, Options: LA , Metric: 0


  Routing Bit Set on this LSA

  LS age: 151

  LS Type: Intra-Area-Prefix-LSA

  Link State ID: 1006

  Advertising Router: 172.16.0.1

  LS Seq Number: 80000001

  Checksum: 0x6E24

  Length: 44

  Referenced LSA Type: 2002

  Referenced Link State ID: 6

  Referenced Advertising Router: 172.16.0.1

  Number of Prefixes: 1

  Prefix Address: 2002:0:1::

  Prefix Length: 64, Options: None, Metric: 0


Router# show ipv6 ospf database router 


OSPFv3 Router with ID (10.0.0.1) (Process ID 1)

Router Link States (Area 0)


  Routing Bit Set on this LSA

  LS age: 5 (DoNotAge)

  Options: (V6-Bit E-Bit R-bit DC-Bit)

  LS Type: Router Links

  Link State ID: 0

  Advertising Router: 10.0.0.1

  LS Seq Number: 80000004

  Checksum: 0xEE5C

  Length: 40

  Area Border Router

  Number of Links: 1


    Link connected to: a Virtual Link

      Link Metric: 10

      Local Interface ID: 70

      Neighbor Interface ID: 71

      Neighbor Router ID: 172.16.0.1


LS age: 162 
Options: (V6-Bit E-Bit R-bit DC-Bit)

LS Type: Router Links

Link State ID: 0

Advertising Router: 172.16.0.1

LS Seq Number: 80000004

Checksum: 0xCE7C

Length: 40

Area Border Router

Number of Links: 1


    Link connected to: a Virtual Link

      Link Metric: 10

      Local Interface ID: 71

      Neighbor Interface ID: 70

      Neighbor Router ID: 10.0.0.1


Router Link States (Area 1)


Routing Bit Set on this LSA

LS age: 176

Options: (V6-Bit E-Bit R-bit DC-Bit)

LS Type: Router Links

Link State ID: 0

Advertising Router: 10.0.0.1

LS Seq Number: 80000003

Checksum: 0xC807

Length: 40

Area Border Router

Number of Links: 1


    Link connected to: a Transit Network

Link Metric: 10

Local Interface ID: 6

Neighbor (DR) Interface ID: 6

Neighbor (DR) Router ID: 172.16.0.1


LS age: 175

Options: (V6-Bit E-Bit R-bit DC-Bit)

LS Type: Router Links

Link State ID: 0

Advertising Router: 172.16.0.1

LS Seq Number: 80000004

Checksum: 0xBD10

Length: 40

Area Border Router

Number of Links: 1


    Link connected to: a Transit Network

Link Metric: 10

Local Interface ID: 6

Neighbor (DR) Interface ID: 6

Neighbor (DR) Router ID: 172.16.0.1


Router# show ipv6 ospf database link adv-router 172.16.0.1


OSPFv3 Router with ID (172.16.0.1) (Process ID 1)

Link (Type-8) Link States (Area 0)


  LS age: 245

  Options: (V6-Bit E-Bit R-bit DC-Bit)

  LS Type: Link-LSA (Interface: GigabitEthernet2/0)

  Link State ID: 10 (Interface ID)

  Advertising Router: 172.16.0.1

  LS Seq Number: 80000002

  Checksum: 0xA0CB

  Length: 56

  Router Priority: 1

  Link Local Address: FE80::A8BB:CCFF:FE00:6F02

  Number of Prefixes: 1

  Prefix Address: 2002:0:2::

  Prefix Length: 64, Options: None


Link (Type-8) Link States (Area 1)


LS age: 250

Options: (V6-Bit E-Bit R-bit DC-Bit)

LS Type: Link-LSA (Interface: GigabitEthernet1/0)

Link State ID: 6 (Interface ID)

Advertising Router: 172.16.0.1

LS Seq Number: 80000001

Checksum: 0x4F94

Length: 44

Router Priority: 1

Link Local Address: FE80::A8BB:CCFF:FE00:6F01

Number of Prefixes: 0

Additional References

The following sections provide references related to the OSPF: SNMP ifIndex Value for Interface ID in OSPFv2 and OSPFv3 Data Fields feature.

Related Documents

Related Topic
Document Title

Configuring OSPF

Configuring OSPF

OSPF commands

Cisco IOS IP Routing: OSPF Command Reference

Cisco IOS master command list, all releases

Cisco IOS Master Command List, All Releases


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 XE software releases , and feature sets, use Cisco MIB Locator found at the following URL:

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


RFCs

RFC
Title

RFC 2328

OSPF Version 2

RFC 2740

OSPF Version 3


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 OSPF: SNMP ifIndex Value for Interface ID in OSPFv2 and OSPFv3 Data Fields

Table 1 lists the release history for this feature.

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

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

Table 1 Feature Information for OSPF: SNMP ifIndex Value for Interface ID in OSPFv2 and OSPFv3 Data Fields 

Feature Name
Releases
Feature Information

OSPF: SNMP ifIndex Value for Interface ID in OSPFv2 and OSPFv3 Data Fields

Cisco IOS XE
Release 2.6

This allows you to choose either the current interface number or the SNMP ifIndex value for the interface ID in OSPFv2 and OSPFv3 data fields. The advantage to using the SNMP MIB-II ifIndex value is that this number corresponds to the number that the user will see reported by SNMP.

The following command is introduced or modified by the feature documented in this module: interface-id snmp-if-index


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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.

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