IP Routing: OSPF Configuration Guide, Cisco IOS Release 15S
SNMP ifIndex Value for Interface ID in OSPFv2 and OSPFv3 Data Fields
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SNMP ifIndex Value for Interface ID in OSPFv2 and OSPFv3 Data Fields

This document describes the configuration command that allows you to use either the current interface number or the SNMP MIB-II interface index (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.

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 at the end of this module.

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 Interface ID in Data Fields

OSPF must be configured on the router.

Information About Interface ID in 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

If you use Simple Network Management Protocol (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 (interface index) 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.
  • When examining 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.
  • When looking at the output of 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 Interface ID in Data Fields

Using SNMP MIB-II ifIndex Numbers

Follow the steps in this task to configure OSPF interfaces to use the SNMP MIB-II ifIndex numbers. These steps work for both OSPFv2 and OSPFv3. All OSPF interfaces must use the SNMP MIB-II ifIndex numbers or the interfaces will not be enabled for OSPF. Therefore, repeat the steps within this task for each OSPF process for which you want the interfaces to use the SNMP MIB-II ifIndex numbers.

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    Do one of the following:

    • router ospf process-id [vrf vpn-name]
    • ipv6 router ospf process-id

    4.    interface-id snmp-if-index

    5.    end

    6.    show snmp mib ifmib ifindex [interface-type] [slot /][port-adapter /][port]


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 Do one of the following:
    • router ospf process-id [vrf vpn-name]
    • ipv6 router ospf process-id


    Example:
    Router(config)# router ospf 4


    Example:
              


    Example:
    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.

     
    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.

     
    Step 6 show snmp mib ifmib ifindex [interface-type] [slot /][port-adapter /][port]


    Example:
    Router# show snmp mib ifmib ifindex Ethernet 0/1
     

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

     

    Configuration Examples for the Interface ID in Data Fields

    Configuring the SNMP ifIndex Value for Interface ID for OSPFv2 Example

    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 s13/0
    Serial13/0: Ifindex = 53

    Configuring the SNMP ifIndex Value for Interface ID for OSPFv3 Example

    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 OSPFv3 data fields.

    Router# show snmp mib ifmib ifindex Ethernet1/0
    Ethernet1/0: Ifindex = 5
    Router#
    Router# show ipv6 ospf int
    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)
    Ethernet2/0 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)
    Ethernet1/0 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#
    Router# show ipv6 ospf data net adv 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 data prefix adv 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#
    Router# show ipv6 ospf data 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#
    Router# show ipv6 ospf data link adv 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: Ethernet2/0)
      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: Ethernet1/0)
      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

    OSPF commands

    Cisco IOS IP Routing: OPSF Command Reference

    OSPF configuration

    "Configuring OSPF"

    Standards

    Standard

    Title

    None

    --

    MIBs

    MIB

    MIBs Link

    None

    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 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 SNMP ifIndex Value for Interface ID in Data Fields

    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 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

    12.4(6)T 12.2(31)SB2 12.2(33)SRB 15.0(1)SY

    This document describes the configuration command that allows you the choice to use 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.

    Glossary

    SNMP --Simple Network Management Protocol (SNMP) is an application layer protocol that facilitates the exchange of management information between network devices. It is part of the Transmission Control Protocol/Internet Protocol (TCP/IP) protocol suite.


    Note


    See Internetworking Terms and Acronyms for terms not included in this glossary.