OSPFv3 Max-Metric Router LSA

The Open Shortest Path First version 3 (OSPFv3) max-metric router link-state advertisement (LSA) feature enables OSPFv3 to advertise its locally generated router LSAs with a maximum metric. The feature allows OSPFv3 processes to converge but not attract transit traffic through the device if there are better alternate paths.

Finding Feature Information

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Information About OSPFv3 Max-Metric Router LSA

OSPFv3 Max-Metric Router LSA

The OSPFv3 max-metric router LSA feature enables OSPFv3 to advertise its locally generated router LSAs with a maximum metric. The feature allows OSPFv3 processes to converge but not attract transit traffic through the device if there are better alternate paths. After a specified timeout or a notification from Border Gateway Protocol (BGP), OSPFv3 advertises the LSAs with normal metrics.

The max-metric LSA control places the OSPFv3 router into the stub router role using its LSA advertisement. A stub router only forwards packets destined to go to its directly connected links. In OSPFv3 networks, a device could become a stub router by advertising large metrics for its connected links, so that the cost of a path through this device becomes larger than that of an alternative path. OSPFv3 stub router advertisement allows a device to advertise the infinity metric (0xFFFF) for its connected links in router LSAs and advertise the normal interface cost if the link is a stub network.

How to Configure OSPFv3 Max-Metric Router LSA

Configuring the OSPFv3 Max-Metric Router LSA

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    router ospfv3 process-id

    4.    address-family ipv6 unicast

    5.    max-metric router-lsa [external-lsa [max-metric-value]] [include-stub] [inter-area-lsas [max-metric-value]] [on-startup {seconds | wait-for-bgp}] [prefix-lsa] [stub-prefix-lsa [max-metric-value]] [summary-lsa [max-metric-value]]

    6.    end

    7.    show ospfv3 [process-id] max-metric


DETAILED STEPS
     Command or ActionPurpose
    Step 1 enable


    Example:
    Device> enable
     

    Enables privileged EXEC mode.

    • Enter your password if prompted.

     
    Step 2 configure terminal


    Example:
    Device# configure terminal
     

    Enters global configuration mode.

     
    Step 3 router ospfv3 process-id


    Example:
    Device(config)# router ospfv3 1
     

    Enables OSPFv3 router configuration mode.

     
    Step 4address-family ipv6 unicast


    Example:
    Device(config)# address-family ipv6 unicast
     

    Configures an instance of the OSPFv3 process in the IPv6 address family.

     
    Step 5 max-metric router-lsa [external-lsa [max-metric-value]] [include-stub] [inter-area-lsas [max-metric-value]] [on-startup {seconds | wait-for-bgp}] [prefix-lsa] [stub-prefix-lsa [max-metric-value]] [summary-lsa [max-metric-value]]


    Example:
    Device(config-router-af)# max-metric router-lsa on-startup wait-for-bgp
     

    Configures a device that is running the OSPFv3 protocol to advertise a maximum metric so that other devices do not prefer the device as an intermediate hop in their SPF calculations.

     
    Step 6 end


    Example:
    Device(config-router-af)# end
     

    Exits address family configuration mode and returns to privileged EXEC mode.

     
    Step 7 show ospfv3 [process-id] max-metric


    Example:
    Device# show ospfv3 1 max-metric
     

    Displays OSPFv3 maximum metric origination information.

     

    Configuration Examples for OSPFv3 Max-Metric Router LSA

    Example: Verifying the OSPFv3 Max-Metric Router LSA

    Router# show ipv6 ospf max-metric 

            OSPFv3 Router with ID (192.1.1.1) (Process ID 1)

 Start time: 00:00:05.886, Time elapsed: 3d02h
 Originating router-LSAs with maximum metric
    Condition: always, State: active

    Additional References for OSPF Nonstop Routing

    Related Documents

    Related Topic

    Document Title

    Cisco IOS commands

    Cisco IOS Master Command List, All Releases

    OSPF commands

    Cisco IOS IP Routing: OSPF Command Reference

    Configuring IETF NSF or Cisco NSF

    “Configuring NSF-OSPF” module in the Cisco IOS High Availability Configuration Guide

    Standard and RFCs

    Standard/RFC

    Title

    RFC 2328

    OSPF Version 2

    RFC 3623

    Graceful OSPF Restart

    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 OSPFv3 Max-Metric Router LSA

    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 OSPFv3 Max-Metric Router LSA

    Feature Name

    Releases

    Feature Information

    OSPFv3 Max-Metric Router LSA

    Cisco IOS XE Release 3.4S

    The OSPFv3 max-metric router LSA feature enables OSPF to advertise its locally generated router LSAs with a maximum metric.

    The following commands were introduced or modified: max-metric router-lsa, show ipv6 ospf max-metric, show ospfv3 max-metric.