IP Routing: BGP Configuration Guide, Cisco IOS XE Release 3S (Cisco ASR 903)
BGP NSR Support for iBGP Peers
Download this chapter
BGP NSR Support for iBGP PeersBGP NSR Support for iBGP Peers
Download the complete book
IP Routing: BGP Configuration Guide, Cisco IOS XE Release 3S (Cisco ASR 903) IP Routing: BGP Configuration Guide, Cisco IOS XE Release 3S (Cisco ASR 903) (PDF - 3 MB)
 Feedback

BGP NSR Support for iBGP Peers

BGP NSR provides BGP nonstop routing (NSR) and nonstop forwarding (NSF) in the event of a switchover from an Active RP to the Standby RP. The BGP NSR Support for iBGP Peers feature provides NSR support for iBGP peers configured under the IPv4 unicast or IPv4 + label address family.

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.

Restrictions on BGP NSR Support for iBGP Peers

This feature applies to iBGP peers configured under IPv4 unicast or IPv4 + label address families.

Information About BGP NSR Support for iBGP Peers

Benefit of BGP NSR Support for iBGP Peers

Nonstop routing is beneficial for iBGP peers because it reduces the likelihood of dropped packets during switchover from the Active RP to the Standby RP. Switchover occurs when the Active RP fails for some reason, and the Standby RP takes control of Active RP operations.

How to Configure BGP NSR Support for iBGP Peers

Making an iBGP Peer NSR-Capable for the IPv4 Address Family

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    router bgp autonomous-system-number

    4.    address-family ipv4 [unicast | vrf vrf-name]

    5.    neighbor ip-address remote-as as-number

    6.    neighbor ip-address activate

    7.    neighbor ip-address ha-mode sso

    8.    end


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 bgp autonomous-system-number


    Example:
    Device(config)# router bgp 4000
     

    Enters router configuration mode for the specified routing process.

     
    Step 4 address-family ipv4 [unicast | vrf vrf-name]

    Example:
    Device(config-router)# address-family ipv4 unicast
     

    Specifies the IPv4 address family and enters address family configuration mode.

    • The unicast keyword specifies the IPv4 unicast address family.
    • The vrf keyword and vrf-name argument specify the name of the virtual routing and forwarding (VRF) instance to associate with subsequent IPv4 address family configuration mode commands.
     
    Step 5 neighbor ip-address remote-as as-number


    Example:
    Device(config-router-af)# neighbor 192.168.1.1 remote-as 4000
     

    Specifies the autonomous system of the neighbor.

     
    Step 6 neighbor ip-address activate


    Example:
    Device(config-router-af)# neighbor 192.168.1.1 activate
     

    Activates the specified peer.

     
    Step 7 neighbor ip-address ha-mode sso


    Example:
    Device(config-router-af)# neighbor 192.168.1.1 ha-mode sso
     

    Configures a BGP neighbor to support BGP NSR with stateful switchover (SSO).

     
    Step 8 end


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

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

     

    Making an iBGP Peer NSR-Capable for the VPNv4 Address Family

    SUMMARY STEPS

      1.    enable

      2.    configure terminal

      3.    router bgp autonomous-system-number

      4.    neighbor ip-address remote-as as-number

      5.    neighbor ip-address ha-mode sso

      6.    address-family vpnv4 [unicast]

      7.    neighbor ip-address activate

      8.    end


    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 bgp autonomous-system-number


      Example:
      Device(config)# router bgp 4000
       

      Enters router configuration mode for the specified routing process.

       
      Step 4 neighbor ip-address remote-as as-number


      Example:
      Device(config-router)# neighbor 192.168.1.1 remote-as 4000
       

      Specifies the autonomous system of the neighbor.

       
      Step 5 neighbor ip-address ha-mode sso


      Example:
      Device(config-router)# neighbor 192.168.1.1 ha-mode sso
       

      Configures a BGP neighbor to support BGP NSR with stateful switchover (SSO).

       
      Step 6 address-family vpnv4 [unicast]

      Example:
      Device(config-router)# address-family VPNv4 unicast
       

      Specifies the VPNv4 address family and enters address family configuration mode.

       
      Step 7 neighbor ip-address activate


      Example:
      Device(config-router-af)# neighbor 192.168.1.1 activate
       

      Activates the specified peer.

       
      Step 8 end


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

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

       

      Making an iBGP Peer NSR Capable at the Router Level

      SUMMARY STEPS

        1.    enable

        2.    configure terminal

        3.    router bgp autonomous-system-number

        4.    neighbor ip-address remote-as as-number

        5.    neighbor ip-address activate

        6.    neighbor ip-address ha-mode sso

        7.    end

        8.    show ip bgp sso summary


      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 bgp autonomous-system-number


        Example:
        Device(config)# router bgp 4000
         

        Enters router configuration mode for the specified routing process.

         
        Step 4 neighbor ip-address remote-as as-number


        Example:
        Device(config-router)# neighbor 192.168.1.1 remote-as 4000
         

        Specifies the autonomous system of the neighbor.

         
        Step 5 neighbor ip-address activate


        Example:
        Device(config-router)# neighbor 192.168.1.1 activate
         

        Activates the specified neighbor.

         
        Step 6 neighbor ip-address ha-mode sso


        Example:
        Device(config-router)# neighbor 192.168.1.1 ha-mode sso
         

        Configures the specified peer to be NSR capable in all of the NSR-supported address families under which that peer has been activated.

         
        Step 7 end


        Example:
        Device(config-router)# end
         

        Exits configuration mode and returns to privileged EXEC mode.

         
        Step 8show ip bgp sso summary


        Example:
        Device# show ip bgp sso summary
         

        (Optional) Displays information about stateful switchover (sso) and whether a peer has NSR enabled or disabled.

         

        Configuration Examples for BGP NSR Support for an iBGP Peer

        Example: Configuring an iBGP Peer To Be NSR Capable

        Configuring an iBGP Peer to Be NSR Capable at the Address Family Level

        router bgp 4000
 address-family ipv4 unicast
 neighbor 192.168.1.1 remote-as 4000
 neighbor 192.168.1.1 activate
 neighbor 192.168.1.1 ha-mode sso

        Configuring an iBGP Peer to Be NSR Capable at the Router Level 

        router bgp 4000
 neighbor 192.168.1.1 remote-as 4000
 neighbor 192.168.1.1 activate 
 neighbor 192.168.1.1 ha-mode sso

        Additional References

        Related Documents

        Related Topic

        Document Title

        Cisco IOS commands

        Cisco IOS Master Command List, All Releases

        BGP commands

        Cisco IOS IP Routing: BGP Command Reference

        BFD commands

        Cisco IOS IP Routing: Protocol Independent Command Reference

        Configuring BFD support for another routing protocol

        IP Routing: BFD Configuration Guide

        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 BGP NSR Support for iBGP Peers

        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 BGP NSR Support for iBGP Peers

        Feature Name

        Releases

        Feature Information

        BGP NSR Support for iBGP Peers

        Cisco IOS XE Release 3.6S

        Cisco IOS XE Release 3.7S

        BGP NSR provides BGP nonstop routing and nonstop forwarding in the event of a switchover from an active RP to the standby RP.

        In Cisco IOS XE Release 3.7S, support was added for the Cisco ASR 903 router.

        The following commands were modified: neighbor ha-mode sso and show ip bgp vpnv4 all sso summary.