OSPFv3 Graceful Restart

The graceful restart feature in Open Shortest Path First version 3 (OSPFv3) allows nonstop data forwarding along routes that are already known while the OSPFv3 routing protocol information is being restored.

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.

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.

Information About OSPFv3 Graceful Restart

OSPFv3 Graceful Restart

The graceful restart feature in OSPFv3 allows nonstop data forwarding along routes that are already known while the OSPFv3 routing protocol information is being restored. A device can participate in graceful restart either in restart mode (such as in a graceful-restart-capable device) or in helper mode (such as in a graceful-restart-aware device).

To perform the graceful restart function, a device must be in high availability (HA) stateful switchover (SSO) mode (that is, dual Route Processor (RP)). A device capable of graceful restart will perform the graceful restart function when the following failures occur:

  • A RP failure that results in switchover to standby RP

  • A planned RP switchover to standby RP

The graceful restart feature requires that neighboring devices be graceful-restart aware.

For further information about SSO and nonstop forwarding (NSF), see the Stateful Switchover and Cisco Nonstop Forwarding documents.

How to Enable OSPFv3 Graceful Restart

Enabling OSPFv3 Graceful Restart on a Graceful-Restart-Capable Router

The task can be performed in Cisco IOS XE 3.4S and later releases.

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    router ospfv3 [process-id]

    4.    graceful-restart [restart-interval interval]


DETAILED STEPS
     Command or ActionPurpose
    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 ospfv3 [process-id]


    Example:
    Router(config)# router ospfv3 1
     

    Enables OSPFv3 router configuration mode for the IPv4 or IPv6 address family.

     
    Step 4 graceful-restart [restart-interval interval]


    Example:
    Router(config-rtr)# graceful-restart
     

    Enables the OSPFv3 graceful restart feature on a graceful-restart-capable router.

     

    Enabling OSPFv3 Graceful Restart on a Graceful-Restart-Capable Router

    The task can be performed in releases prior to Cisco IOS XE Release 3.4S.

    SUMMARY STEPS

      1.    enable

      2.    configure terminal

      3.    ipv6 router ospf process-id

      4.    graceful-restart [restart-interval interval]


    DETAILED STEPS
       Command or ActionPurpose
      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 ipv6 router ospf process-id


      Example:
      Router(config)# ipv6 router ospf 1
       

      Enables OSPFv3 router configuration mode.

       
      Step 4 graceful-restart [restart-interval interval]


      Example:
      Router(config-rtr)# graceful-restart
       

      Enables the OSPFv3 graceful restart feature on a graceful-restart-capable router.

       

      Enabling OSPFv3 Graceful Restart on a Graceful-Restart-Aware Router

      The task can be performed in Cisco IOS XE Release 3.4S and later releases.

      SUMMARY STEPS

        1.    enable

        2.    configure terminal

        3.    router ospfv3 [process-id]

        4.    graceful-restart helper {disable | strict-lsa-checking


      DETAILED STEPS
         Command or ActionPurpose
        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 ospfv3 [process-id]


        Example:
        Router(config)# router ospfv3 1
         

        Enables OSPFv3 router configuration mode for the IPv4 or IPv6 address family.

         
        Step 4 graceful-restart helper {disable | strict-lsa-checking


        Example:
        Router(config-rtr)# graceful-restart helper strict-lsa-checking
         

        Enables the OSPFv3 graceful restart feature on a graceful-restart-aware router.

         

        Example:

        What to Do Next

        Enabling OSPFv3 Graceful Restart on a Graceful-Restart-Aware Router

        The task can be performed in releases prior to Cisco IOS XE Release 3.4S.

        SUMMARY STEPS

          1.    enable

          2.    configure terminal

          3.    ipv6 router ospf process-id

          4.    graceful-restart helper {disable | strict-lsa-checking


        DETAILED STEPS
           Command or ActionPurpose
          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 ipv6 router ospf process-id


          Example:
          Router(config)# ipv6 router ospf 1
           

          Enables OSPFv3 router configuration mode.

           
          Step 4 graceful-restart helper {disable | strict-lsa-checking


          Example:
          Router(config-rtr)# graceful-restart helper strict-lsa-checking
           

          Enables the OSPFv3 graceful restart feature on a graceful-restart-aware router.

           
          Example:

          What to Do Next

          Configuration Examples for OSPFv3 Graceful Restart

          Example: Enabling OSPFv3 Graceful Restart

          Router# show ipv6 ospf graceful-restart
Routing Process "ospf 1"
 Graceful Restart enabled
    restart-interval limit: 120 sec, last restart 00:00:15 ago (took 36 secs)
  Graceful Restart helper support enabled
  Router status : Active
  Router is running in SSO mode
  OSPF restart state : NO_RESTART 
  Router ID 10.1.1.1, checkpoint Router ID 10.0.0.0

          The following example shows OSPFv3 information with graceful-restart helper support enabled on a graceful-restart-aware router. 

          Router# show ospfv3                 
 Routing Process "ospfv3 1" with ID 10.0.0.1
 Supports IPv6 Address Family
 Event-log enabled, Maximum number of events: 1000, Mode: cyclic
 Initial SPF schedule delay 5000 msecs
 Minimum hold time between two consecutive SPFs 10000 msecs
 Maximum wait time between two consecutive SPFs 10000 msecs
 Minimum LSA interval 5 secs
 Minimum LSA arrival 1000 msecs
 LSA group pacing timer 240 secs
 Interface flood pacing timer 33 msecs
 Retransmission pacing timer 66 msecs
 Number of external LSA 0. Checksum Sum 0x000000
 Number of areas in this router is 0. 0 normal 0 stub 0 nssa
 Graceful restart helper support enabled
 Reference bandwidth unit is 100 mbps
 Relay willingness value is 128
 Pushback timer value is 2000 msecs
 Relay acknowledgement timer value is 1000 msecs
 LSA cache Disabled : current count 0, maximum 1000
 ACK cache Disabled : current count 0, maximum 1000
 Selective Peering is not enabled
 Hello requests and responses will be sent multicast

          Additional References

          Related Documents

          Related Topic

          Document Title

          IPv6 addressing and connectivity

          IPv6 Configuration Guide

          Stateful switchover and Cisco nonstop forwarding

          High Availability Configuration Guide

          Cisco IOS commands

          Cisco IOS Master Commands List, All Releases

          IPv6 commands

          Cisco IOS IPv6 Command Reference

          Cisco IOS IPv6 features

          Cisco IOS IPv6 Feature Mapping

          OSPFv3 Graceful Restart

          “OSPF RFC 3623 Graceful Restart Helper Mode” module

          OSPFv3 Graceful Restart

          “Configuring OSPF ” module

          OSPFv3 Graceful Restart

          “NSF-OSPF RFC 3623 OSPF Graceful Restart ” module

          Standards and RFCs

          Standard/RFC

          Title

          RFCs for IPv6

          IPv6 RFCs

          MIBs

          MIB

          MIBs Link

          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

          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 Graceful Restart

          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 Graceful Restart

          Feature Name

          Releases

          Feature Information

          OSPFv3 Graceful Restart

          Cisco IOS XE Release 2.1

          The graceful restart feature in OSPFv3 allows nonstop data forwarding along routes that are already known while the OSPFv3 routing protocol information is being restored.

          The following commands were introduced or modified: graceful-restart, graceful-restart helper, ipv6 router ospf, router ospfv3, show ipv6 ospf graceful-restart, show ospfv3 graceful-restart.