Contents

Per-VRF Assignment of BGP Router ID

The Per-VRF Assignment of BGP Router ID feature introduces the ability to have VRF-to-VRF peering in Border Gateway Protocol (BGP) on the same router. BGP is designed to refuse a session with itself because of the router ID check. The per-VRF assignment feature allows a separate router ID per VRF using a new keyword in the existing bgp router-id command. The router ID can be manually configured for each VRF or can be assigned automatically either globally under address family configuration mode or for each VRF.

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 Per-VRF Assignment of BGP Router ID

Before you configure this feature, Cisco Express Forwarding (CEF) or distributed CEF (dCEF) must be enabled in the network, and basic BGP peering is assumed to be running in the network.

Information About Per-VRF Assignment of BGP Router ID

BGP Router ID

The BGP router identifier (ID) is a 4-byte field that is set to the highest IP address on the router. Loopback interface addresses are considered before physical interface addresses because loopback interfaces are more stable than physical interfaces. The BGP router ID is used in the BGP algorithm for determining the best path to a destination where the preference is for the BGP router with the lowest router ID. It is possible to manually configure the BGP router ID using the bgp router-id command to influence the best path algorithm.

Per-VRF Router ID Assignment

The Per-VRF Assignment of BGP Router ID feature introduces the ability to have VRF-to-VRF peering in Border Gateway Protocol (BGP) on the same router. BGP is designed to refuse a session with itself because of the router ID check. The Per-VRF Assignment of BGP Router ID feature allows a separate router ID per VRF using a new keyword in the existing bgp router-id command. The router ID can be manually configured for each VRF or can be assigned automatically either globally under address family configuration mode or for each VRF.

Route Distinguisher

A route distinguisher (RD) creates routing and forwarding tables and specifies the default route distinguisher for a VPN. The RD is added to the beginning of an IPv4 prefix to change it into a globally unique VPN-IPv4 prefix. An RD can be composed in one of two ways: with an autonomous system number and an arbitrary number or with an IP address and an arbitrary number.

You can enter an RD in either of these formats:

  • Enter a 16-bit autonomous system number, a colon, and a 32-bit number. For example:

45000:3

  • Enter a 32-bit IP address, a colon, and a 16-bit number. For example:

192.168.10.15:1

How to Configure Per-VRF Assignment of BGP Router ID

Configuring VRF Instances

Perform this task to configure VRF instances to be used with the Per-VRF Assignment of Router ID tasks. In this task, a VRF instance named vrf_trans is created. To make the VRF functional, a route distinguisher is created. When the route distinguisher is created, the routing and forwarding tables are created for the VRF instance named vrf_trans.

Before You Begin

This task assumes that you have CEF or dCEF enabled.

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    ip vrf vrf-name

    4.    rd route-distinguisher

    5.    route-target [import | both] route-target-ext-community

    6.    route-target [export | both] route-target-ext-community

    7.    exit

    8.    Repeat Step 3 through Step 7 for each VRF to be defined.


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 ip vrf vrf-name


    Example:
    Device(config)# ip vrf vrf_trans
     

    Defines a VRF instance and enters VRF configuration mode.

     
    Step 4 rd route-distinguisher


    Example:
    Device(config-vrf)# rd 45000:2
     

    Creates routing and forwarding tables for a VRF and specifies the default RD for a VPN.

    • Use the route-distinguisher argument to specify the default RD for a VPN. There are two formats you can use to specify an RD. For more details, see the “Route Distinguisher” section.

    • In this example, the RD uses an autonomous system number with the number 2 after the colon.

     
    Step 5 route-target [import | both] route-target-ext-community


    Example:
    Device(config-vrf)# route-target import 55000:5
     

    Creates a route-target extended community for a VRF.

    • Use the import keyword to import routing information from the target VPN extended community.

    • Use the both keyword to both import routing information from and export routing information to the target VPN extended community.

    • Use the route-target-ext-community argument to specify the VPN extended community.

     
    Step 6 route-target [export | both] route-target-ext-community


    Example:
    Device(config-vrf)# route-target export 55000:1
     

    Creates a route-target extended community for a VRF.

    • Use the export keyword to export routing information to the target VPN extended community.

    • Use the both keyword to both import routing information from and export routing information to the target VPN extended community.

    • Use the route-target-ext-community argument to specify the VPN extended community.

     
    Step 7 exit


    Example:
    Device(config-vrf)# exit
     

    Exits VRF configuration mode and returns to global configuration mode.

     
    Step 8 Repeat Step 3 through Step 7 for each VRF to be defined.  

     

    Associating VRF Instances with Interfaces

    Perform this task to associate VRF instances with interfaces to be used with the per-VRF assignment tasks. In this task, a VRF instance named vrf_trans is associated with a serial interface.

    Make a note of the IP addresses for any interface to which you want to associate a VRF instance because the ip vrf forwarding command removes the IP address. Step 8 allows you to reconfigure the IP address.

    Before You Begin

    • This task assumes that you have CEF or dCEF enabled.

    • This task assumes that VRF instances have been configured as shown in preceding “Configuring VRF Instances” task in this module.

    SUMMARY STEPS

      1.    enable

      2.    configure terminal

      3.    interface type number

      4.    ip address ip-address mask [secondary]

      5.    exit

      6.    interface type number

      7.    ip vrf forwarding vrf-name [downstream vrf-name2]

      8.    ip address ip-address mask [secondary]

      9.    Repeat Step 5 through Step 8 for each VRF to be associated with an interface.

      10.    end

      11.    show ip vrf [brief | detail | interfaces | id] [vrf-name]


    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 interface type number


      Example:
      Router(config)# interface loopback0
       

      Configures an interface type and enters interface configuration mode.

      • In this example, loopback interface 0 is configured.

       
      Step 4 ip address ip-address mask [secondary]


      Example:
      Router(config-if)# ip address 172.16.1.1 255.255.255.255
       

      Configures an IP address.

      • In this example, the loopback interface is configured with an IP address of 172.16.1.1.

       
      Step 5 exit


      Example:
      Router(config-if)# exit
       

      Exits interface configuration mode and returns to global configuration mode.

       
      Step 6 interface type number


      Example:
      Router(config)# interface serial2/0
       

      Configures an interface type and enters interface configuration mode.

      • In this example, serial interface 2/0 is configured.

       
      Step 7 ip vrf forwarding vrf-name [downstream vrf-name2]


      Example:
      Router(config-if)# ip vrf forwarding vrf_trans
       

      Associates a VRF with an interface or subinterface.

      • In this example, the VRF named vrf_trans is associated with serial interface 2/0.

      Note   

      Executing this command on an interface removes the IP address. The IP address should be reconfigured.

       
      Step 8 ip address ip-address mask [secondary]


      Example:
      Router(config-if)# ip address 192.168.4.1 255.255.255.0
       

      Configures an IP address.

      • In this example, serial interface 2/0 is configured with an IP address of 192.168.4.1.

       
      Step 9 Repeat Step 5 through Step 8 for each VRF to be associated with an interface.  

      --

       
      Step 10 end


      Example:
      Router(config-if)# end
       

      Exits interface configuration mode and returns to privileged EXEC mode.

       
      Step 11 show ip vrf [brief | detail | interfaces | id] [vrf-name]

      Example:
      Router# show ip vrf interfaces
       

      (Optional) Displays the set of defined VRFs and associated interfaces.

      • In this example, the output from this command shows the VRFs that have been created and their associated interfaces.

       

      Examples

      The following output show s that two VRF instances named vrf_trans and vrf_users were configured on two serial interfaces. 

      Router# show ip vrf interfaces

Interface         IP-Address      VRF                      Protocol
Serial2           192.168.4.1     vrf_trans                up      
Serial3           192.168.5.1     vrf_user                 up

      Manually Configuring a BGP Router ID per VRF

      Perform this task to manually configure a BGP router ID for each VRF. In this task, several address family configurations are shown and the router ID is configured in the IPv4 address family mode for one VRF instance. Step 22 shows you how to repeat certain steps to permit the configuration of more than one VRF on the same router.

      Before You Begin

      This task assumes that you have previously created the VRF instances and associated them with interfaces. For more details, see the “Configuring VRF Instances” task and the “Associating VRF Instances with Interfaces” task earlier in this module.

      SUMMARY STEPS

        1.    enable

        2.    configure terminal

        3.    router bgp autonomous-system-number

        4.    no bgp default ipv4-unicast

        5.    bgp log-neighbor-changes

        6.    neighbor {ip-address | peer-group-name} remote-as autonomous-system-number

        7.    neighbor {ip-address | peer-group-name} update-source interface-type interface-number

        8.    address-family {ipv4 [mdt | multicast | unicast [vrf vrf-name] | vrf vrf-name] | vpnv4 [unicast]}

        9.    neighbor {ip-address | peer-group-name} activate

        10.    neighbor {ip-address | peer-group-name} send-community {both | standard | extended}

        11.    exit-address-family

        12.    address-family {ipv4 [mdt | multicast | unicast [vrf vrf-name] | vrf vrf-name] | vpnv4 [unicast]}

        13.    redistribute connected

        14.    neighbor {ip-address | peer-group-name} remote-as autonomous-system-number

        15.    neighbor ip-address local-as autonomous-system-number [no-prepend [replace-as [dual-as]]]

        16.    neighbor {ip-address | peer-group-name} ebgp-multihop [ttl]

        17.    neighbor {ip-address | peer-group-name} activate

        18.    neighbor ip-address allowas-in [number]

        19.    no auto-summary

        20.    no synchronization

        21.    bgp router-id {ip-address | auto-assign}

        22.    Repeat Step 11 to Step 21 to configure another VRF instance.

        23.    end

        24.    show ip bgp vpnv4 {all | rd route-distinguisher | vrf vrf-name}


      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 bgp autonomous-system-number


        Example:
        Router(config)# router bgp 45000
         

        Enters router configuration mode for the specified routing process.

         
        Step 4 no bgp default ipv4-unicast


        Example:
        Router(config-router)# no bgp default ipv4-unicast
         

        Disables the IPv4 unicast address family for the BGP routing process.

        Note   

        Routing information for the IPv4 unicast address family is advertised by default for each BGP routing session configured with the neighbor remote-as router configuration command unless you configure the no bgp default ipv4-unicast router configuration command before configuring the neighbor remote-as command. Existing neighbor configurations are not affected.

         
        Step 5 bgp log-neighbor-changes


        Example:
        Router(config-router)# bgp log-neighbor-changes
         

        Enables logging of BGP neighbor resets.

         
        Step 6 neighbor {ip-address | peer-group-name} remote-as autonomous-system-number


        Example:
        Router(config-router)# neighbor 192.168.1.1 remote-as 45000
         

        Adds the IP address or peer group name of the neighbor in the specified autonomous system to the IPv4 multiprotocol BGP neighbor table of the local router.

        • If the autonomous-system-number argument matches the autonomous system number specified in the router bgp command, the neighbor is an internal neighbor.

        • If the autonomous-system-number argument does not match the autonomous system number specified in the router bgp command, the neighbor is an external neighbor.

        • In this example, the neighbor is an internal neighbor.

         
        Step 7 neighbor {ip-address | peer-group-name} update-source interface-type interface-number


        Example:
        Router(config-router)# neighbor 192.168.1.1 update-source loopback0
         

        Allows BGP sessions to use any operational interface for TCP connections.

        • In this example, BGP TCP connections for the specified neighbor are sourced with the IP address of the loopback interface rather than the best local address.

         
        Step 8 address-family {ipv4 [mdt | multicast | unicast [vrf vrf-name] | vrf vrf-name] | vpnv4 [unicast]}


        Example:
        Router(config-router)# address-family vpnv4
         

        Enters address family configuration mode to configure BGP peers to accept address-family-specific configurations.

        • The example creates a VPNv4 address family session.

         
        Step 9 neighbor {ip-address | peer-group-name} activate


        Example:
        Router(config-router-af)# neighbor 172.16.1.1 activate
         

        Activates the neighbor under the VPNv4 address family.

        • In this example, the neighbor 172.16.1.1 is activated.

         
        Step 10 neighbor {ip-address | peer-group-name} send-community {both | standard | extended}


        Example:
        Router(config-router-af)# neighbor 172.16.1.1 send-community extended
         

        Specifies that a communities attribute should be sent to a BGP neighbor.

        • In this example, an extended communities attribute is sent to the neighbor at 172.16.1.1.

         
        Step 11 exit-address-family


        Example:
        Router(config-router-af)# exit-address-family
         

        Exits address family configuration mode and returns to router configuration mode.

         
        Step 12 address-family {ipv4 [mdt | multicast | unicast [vrf vrf-name] | vrf vrf-name] | vpnv4 [unicast]}


        Example:
        Router(config-router)# address-family ipv4 vrf vrf_trans
         

        Enters address family configuration mode to configure BGP peers to accept address-family-specific configurations.

        • The example specifies that the VRF instance named vrf_trans is to be associated with subsequent IPv4 address family configuration commands.

         
        Step 13 redistribute connected


        Example:
        Router(config-router-af)# redistribute connected
         

        Redistributes from one routing domain into another routing domain.

        • In this example, the connected keyword is used to represent routes that are established automatically when IP is enabled on an interface.

        • Only the syntax applicable to this step is displayed. For more details, see the Cisco IOS IP Routing: BGP Command Reference.

         
        Step 14 neighbor {ip-address | peer-group-name} remote-as autonomous-system-number


        Example:
        Router(config-router-af)# neighbor 192.168.1.1 remote-as 40000
         

        Adds the IP address or peer group name of the neighbor in the specified autonomous system to the IPv4 multiprotocol BGP neighbor table of the local router.

        • If the autonomous-system-number argument matches the autonomous system number specified in the router bgp command, the neighbor is an internal neighbor.

        • If the autonomous-system-number argument does not match the autonomous system number specified in the router bgp command, the neighbor is an external neighbor.

        • In this example, the neighbor at 192.168.1.1 is an external neighbor.

         
        Step 15 neighbor ip-address local-as autonomous-system-number [no-prepend [replace-as [dual-as]]]


        Example:
        Router(config-router-af)# neighbor 192.168.1.1 local-as 50000 no-prepend
         

        Customizes the AS_PATH attribute for routes received from an eBGP neighbor.

        • The autonomous system number from the local BGP routing process is prepended to all external routes by default.

        • Use the no-prepend keyword to not prepend the local autonomous system number to any routes received from the eBGP neighbor.

        • In this example, routes from the neighbor at 192.168.1.1 will not contain the local autonomous system number.

         
        Step 16 neighbor {ip-address | peer-group-name} ebgp-multihop [ttl]


        Example:
        Router(config-router-af)# neighbor 192.168.1.1 ebgp-multihop 2
         

        Accepts and attempts BGP connections to external peers residing on networks that are not directly connected.

        • In this example, BGP is configured to allow connections to or from neighbor 192.168.1.1, which resides on a network that is not directly connected.

         
        Step 17 neighbor {ip-address | peer-group-name} activate


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

        Activates the neighbor under the IPV4 address family.

        • In this example, the neighbor 192.168.1.1 is activated.

         
        Step 18 neighbor ip-address allowas-in [number]


        Example:
        Router(config-router-af)# neighbor 192.168.1.1 allowas-in 1
         

        Configures provider edge (PE) routers to allow the readvertisement of all prefixes that contain duplicate autonomous system numbers.

        • In the example, the PE router with autonomous system number 45000 is configured to allow prefixes from the VRF vrf-trans. The neighboring PE router with the IP address 192.168.1.1 is set to be readvertised once to other PE routers with the same autonomous system number.

         
        Step 19 no auto-summary


        Example:
        Router(config-router-af)# no auto-summary
         

        Disables automatic summarization and sends subprefix routing information across classful network boundaries.

         
        Step 20 no synchronization


        Example:
        Router(config-router-af)# no synchronization
         

        Enables the Cisco IOS software to advertise a network route without waiting for synchronization with an Internal Gateway Protocol (IGP).

         
        Step 21 bgp router-id {ip-address | auto-assign}


        Example:
        Router(config-router-af)# bgp router-id 10.99.1.1
         

        Configures a fixed router ID for the local BGP routing process.

        • In this example, the specified BGP router ID is assigned for the VRF instance associated with this IPv4 address family configuration.

         
        Step 22 Repeat Step 11 to Step 21 to configure another VRF instance.  

        --

         
        Step 23 end


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

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

         
        Step 24 show ip bgp vpnv4 {all | rd route-distinguisher | vrf vrf-name}


        Example:
        Router# show ip bgp vpnv4 all
         

        (Optional) Displays VPN address information from the BGP table.

        • In this example, the complete VPNv4 database is displayed.

        Note   

        Only the syntax applicable to this task is used in this example. For more details, see the Cisco IOS Multiprotocol Label Switching Command Reference.

         

        Examples

        The following sample output assumes that two VRF instances named vrf_trans and vrf_user were configured each with a separate router ID. The router ID is shown next to the VRF name. 

        Router# show ip bgp vpnv4 all

BGP table version is 5, local router ID is 172.17.1.99
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
   Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 1:1 (default for vrf vrf_trans) VRF Router ID 10.99.1.2
*> 192.168.4.0      0.0.0.0                  0         32768 ?
Route Distinguisher: 42:1 (default for vrf vrf_user) VRF Router ID 10.99.1.1
*> 192.168.5.0      0.0.0.0                  0         32768 ?

        Automatically Assigning a BGP Router ID per VRF

        Perform this task to automatically assign a BGP router ID for each VRF. In this task, a loopback interface is associated with a VRF and the bgp router-id command is configured at the router configuration level to automatically assign a BGP router ID to all VRF instances. Step 9 shows you how to repeat certain steps to configure each VRF that is to be associated with an interface. Step 30 shows you how to configure more than one VRF on the same router.

        Before You Begin

        This task assumes that you have previously created the VRF instances as shown in the “Configuring VRF Instances” task in this module.

        SUMMARY STEPS

          1.    enable

          2.    configure terminal

          3.    interface type number

          4.    ip address ip-address mask [secondary]

          5.    exit

          6.    interface type number

          7.    ip vrf forwarding vrf-name [downstream vrf-name2]

          8.    ip address ip-address mask [secondary]

          9.    Repeat Step 5 through Step 8 for each VRF to be associated with an interface.

          10.    exit

          11.    router bgp autonomous-system-number

          12.    bgp router-id {ip-address | vrf auto-assign}

          13.    no bgp default ipv4-unicast

          14.    bgp log-neighbor-changes

          15.    neighbor {ip-address | peer-group-name} remote-as autonomous-system-number

          16.    neighbor {ip-address | peer-group-name} update-source interface-type interface-number

          17.    address-family {ipv4 [mdt | multicast | unicast [vrf vrf-name] | vrf vrf-name] | vpnv4 [unicast]}

          18.    neighbor {ip-address | peer-group-name} activate

          19.    neighbor {ip-address | peer-group-name} send-community {both | standard | extended}

          20.    exit-address-family

          21.    address-family {ipv4 [mdt | multicast | unicast [vrf vrf-name] | vrf vrf-name] | vpnv4 [unicast]}

          22.    redistribute connected

          23.    neighbor {ip-address | peer-group-name} remote-as autonomous-system-number

          24.    neighbor ip-address local-as autonomous-system-number [no-prepend [replace-as [dual-as]]]

          25.    neighbor {ip-address | peer-group-name} ebgp-multihop [ttl]

          26.    neighbor {ip-address | peer-group-name} activate

          27.    neighbor ip-address allowas-in [number]

          28.    no auto-summary

          29.    no synchronization

          30.    Repeat Step 20 to Step 29 to configure another VRF instance.

          31.    end

          32.    show ip bgp vpnv4 {all | rd route-distinguisher | vrf vrf-name}


        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 interface type number


          Example:
          Router(config)# interface loopback0
           

          Configures an interface type and enters interface configuration mode.

          • In this example, loopback interface 0 is configured.

           
          Step 4 ip address ip-address mask [secondary]


          Example:
          Router(config-if)# ip address 172.16.1.1 255.255.255.255
           

          Configures an IP address.

          • In this example, the loopback interface is configured with an IP address of 172.16.1.1.

           
          Step 5 exit


          Example:
          Router(config-if)# exit
           

          Exits interface configuration mode and returns to global configuration mode.

           
          Step 6 interface type number


          Example:
          Router(config)# interface loopback1
           

          Configures an interface type and enters interface configuration mode.

          • In this example, loopback interface 1 is configured.

           
          Step 7 ip vrf forwarding vrf-name [downstream vrf-name2]


          Example:
          Router(config-if)# ip vrf forwarding vrf_trans
           

          Associates a VRF with an interface or subinterface.

          • In this example, the VRF named vrf_trans is associated with loopback interface 1.

          Note   

          Executing this command on an interface removes the IP address. The IP address should be reconfigured.

           
          Step 8 ip address ip-address mask [secondary]


          Example:
          Router(config-if)# ip address 10.99.1.1 255.255.255.255
           

          Configures an IP address.

          • In this example, loopback interface 1 is configured with an IP address of 10.99.1.1.

           
          Step 9 Repeat Step 5 through Step 8 for each VRF to be associated with an interface.  

          --

           
          Step 10 exit


          Example:
          Router(config-if)# exit
           

          Exits interface configuration mode and returns to global configuration mode.

           
          Step 11 router bgp autonomous-system-number


          Example:
          Router(config)# router bgp 45000
           

          Enters router configuration mode for the specified routing process.

           
          Step 12 bgp router-id {ip-address | vrf auto-assign}


          Example:
          Router(config-router)# bgp router-id vrf auto-assign
           

          Configures a fixed router ID for the local BGP routing process.

          • In this example, a BGP router ID is automatically assigned for each VRF instance.

           
          Step 13 no bgp default ipv4-unicast


          Example:
          Router(config-router)# no bgp default ipv4-unicast
           

          Disables the IPv4 unicast address family for the BGP routing process.

          Note   

          Routing information for the IPv4 unicast address family is advertised by default for each BGP routing session configured with the neighbor remote-as router configuration command unless you configure the no bgp default ipv4-unicast router configuration command before configuring the neighbor remote-as command. Existing neighbor configurations are not affected.

           
          Step 14 bgp log-neighbor-changes


          Example:
          Router(config-router)# bgp log-neighbor-changes
           

          Enables logging of BGP neighbor resets.

           
          Step 15 neighbor {ip-address | peer-group-name} remote-as autonomous-system-number


          Example:
          Router(config-router)# neighbor 192.168.1.1 remote-as 45000
           

          Adds the IP address or peer group name of the neighbor in the specified autonomous system to the IPv4 multiprotocol BGP neighbor table of the local router.

          • If the autonomous-system-number argument matches the autonomous system number specified in the router bgp command, the neighbor is an internal neighbor.

          • If the autonomous-system-number argument does not match the autonomous system number specified in the router bgp command, the neighbor is an external neighbor.

          • In this example, the neighbor is an internal neighbor.

           
          Step 16 neighbor {ip-address | peer-group-name} update-source interface-type interface-number


          Example:
          Router(config-router)# neighbor 192.168.1.1 update-source loopback0
           

          Allows BGP sessions to use any operational interface for TCP connections.

          • In this example, BGP TCP connections for the specified neighbor are sourced with the IP address of the loopback interface rather than the best local address.

           
          Step 17 address-family {ipv4 [mdt | multicast | unicast [vrf vrf-name] | vrf vrf-name] | vpnv4 [unicast]}


          Example:
          Router(config-router)# address-family vpnv4
           

          Enters address family configuration mode to configure BGP peers to accept address-family-specific configurations.

          • The example creates a VPNv4 address family session.

           
          Step 18 neighbor {ip-address | peer-group-name} activate


          Example:
          Router(config-router-af)# neighbor 172.16.1.1 activate
           

          Activates the neighbor under the VPNv4 address family.

          • In this example, the neighbor 172.16.1.1 is activated.

           
          Step 19 neighbor {ip-address | peer-group-name} send-community {both | standard | extended}


          Example:
          Router(config-router-af)# neighbor 172.16.1.1 send-community extended
           

          Specifies that a communities attribute should be sent to a BGP neighbor.

          • In this example, an extended communities attribute is sent to the neighbor at 172.16.1.1.

           
          Step 20 exit-address-family


          Example:
          Router(config-router-af)# exit-address-family
           

          Exits address family configuration mode and returns to router configuration mode.

           
          Step 21 address-family {ipv4 [mdt | multicast | unicast [vrf vrf-name] | vrf vrf-name] | vpnv4 [unicast]}


          Example:
          Router(config-router)# address-family ipv4 vrf vrf_trans
           

          Enters address family configuration mode to configure BGP peers to accept address-family-specific configurations.

          • The example specifies that the VRF instance named vrf_trans is to be associated with subsequent IPv4 address family configuration mode commands.

           
          Step 22 redistribute connected


          Example:
          Router(config-router-af)# redistribute connected
           

          Redistributes from one routing domain into another routing domain.

          • In this example, the connected keyword is used to represent routes that are established automatically when IP is enabled on an interface.

          • Only the syntax applicable to this step is displayed. For more details, see the Cisco IOS IP Routing: BGP Command Reference.

           
          Step 23 neighbor {ip-address | peer-group-name} remote-as autonomous-system-number


          Example:
          Router(config-router-af)# neighbor 192.168.1.1 remote-as 40000
           

          Adds the IP address or peer group name of the neighbor in the specified autonomous system to the IPv4 multiprotocol BGP neighbor table of the local router.

          • If the autonomous-system-number argument matches the autonomous system number specified in the router bgp command, the neighbor is an internal neighbor.

          • If the autonomous-system-number argument does not match the autonomous system number specified in the router bgp command, the neighbor is an external neighbor.

          • In this example, the neighbor at 192.168.1.1 is an external neighbor.

           
          Step 24 neighbor ip-address local-as autonomous-system-number [no-prepend [replace-as [dual-as]]]


          Example:
          Router(config-router-af)# neighbor 192.168.1.1 local-as 50000 no-prepend
           

          Customizes the AS_PATH attribute for routes received from an eBGP neighbor.

          • The autonomous system number from the local BGP routing process is prepended to all external routes by default.

          • Use the no-prepend keyword to not prepend the local autonomous system number to any routes received from the eBGP neighbor.

          • In this example, routes from the neighbor at 192.168.1.1 will not contain the local autonomous system number.

           
          Step 25 neighbor {ip-address | peer-group-name} ebgp-multihop [ttl]


          Example:
          Router(config-router-af)# neighbor 192.168.1.1 ebgp-multihop 2
           

          Accepts and attempts BGP connections to external peers residing on networks that are not directly connected.

          • In this example, BGP is configured to allow connections to or from neighbor 192.168.1.1, which resides on a network that is not directly connected.

           
          Step 26 neighbor {ip-address | peer-group-name} activate


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

          Activates the neighbor under the IPV4 address family.

          • In this example, the neighbor 192.168.1.1 is activated.

           
          Step 27 neighbor ip-address allowas-in [number]


          Example:
          Router(config-router-af)# neighbor 192.168.1.1 allowas-in 1
           

          Configures provider edge (PE) routers to allow the readvertisement of all prefixes that contain duplicate autonomous system numbers.

          • In the example, the PE router with autonomous system number 45000 is configured to allow prefixes from the VRF vrf-trans. The neighboring PE router with the IP address 192.168.1.1 is set to be readvertised once to other PE routers with the same autonomous system number.

           
          Step 28 no auto-summary


          Example:
          Router(config-router-af)# no auto-summary
           

          Disables automatic summarization and sends subprefix routing information across classful network boundaries.

           
          Step 29 no synchronization


          Example:
          Router(config-router-af)# no synchronization
           

          Enables the Cisco IOS software to advertise a network route without waiting for synchronization with an Internal Gateway Protocol (IGP).

           
          Step 30 Repeat Step 20 to Step 29 to configure another VRF instance.  

          --

           
          Step 31 end


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

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

           
          Step 32 show ip bgp vpnv4 {all | rd route-distinguisher | vrf vrf-name}


          Example:
          Router# show ip bgp vpnv4 all
           

          (Optional) Displays VPN address information from the BGP table.

          • In this example, the complete VPNv4 database is displayed.

          Note   

          Only the syntax applicable to this task is used in this example. For more details, see the Cisco IOS Multiprotocol Label Switching Command Reference.

           

          Examples

          The following sample output assumes that two VRF instances named vrf_trans and vrf_user were configured, each with a separate router ID. The router ID is shown next to the VRF name. 

          Router# show ip bgp vpnv4 all

BGP table version is 43, local router ID is 172.16.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
   Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 1:1 (default for vrf vrf_trans) VRF Router ID 10.99.1.2
*> 172.22.0.0       0.0.0.0                  0         32768 ?
r> 172.23.0.0       172.23.1.1               0             0 3 1 ?
*>i10.21.1.1/32     192.168.3.1              0    100      0 2 i
*> 10.52.1.0/24     172.23.1.1                             0 3 1 ?
*> 10.52.2.1/32     172.23.1.1                             0 3 1 3 i
*> 10.52.3.1/32     172.23.1.1                             0 3 1 3 i
*> 10.99.1.1/32     172.23.1.1               0             0 3 1 ?
*> 10.99.1.2/32     0.0.0.0                  0         32768 ?
Route Distinguisher: 10:1
*>i10.21.1.1/32     192.168.3.1              0    100      0 2 i
Route Distinguisher: 42:1 (default for vrf vrf_user) VRF Router ID 10.99.1.1
r> 172.22.0.0       172.22.1.1               0             0 2 1 ?
*> 172.23.0.0       0.0.0.0                  0         32768 ?
*> 10.21.1.1/32     172.22.1.1                             0 2 1 2 i
*>i10.52.1.0/24     192.168.3.1              0    100      0 ?
*>i10.52.2.1/32     192.168.3.1              0    100      0 3 i
*>i10.52.3.1/32     192.168.3.1              0    100      0 3 i
*> 10.99.1.1/32     0.0.0.0                  0         32768 ?
*> 10.99.1.2/32     172.22.1.1               0             0 2 1 ?

          Configuration Examples for Per-VRF Assignment of BGP Router ID

          Example: Manually Configuring a BGP Router ID per VRF

          The following example shows how to configure two VRFs—vrf_trans and vrf_user—with sessions between each other on the same router. The BGP router ID for each VRF is configured manually under separate IPv4 address families. The show ip bgp vpnv4 command can be used to verify that the router IDs have been configured for each VRF. The configuration starts in global configuration mode. 

          ip vrf vrf_trans
 rd 45000:1
 route-target export 50000:50
 route-target import 40000:1
!
ip vrf vrf_user
 rd 65500:1
 route-target export 65500:1
 route-target import 65500:1
!
interface Loopback0
 ip address 10.1.1.1 255.255.255.255
!
interface Ethernet0/0
 ip vrf forwarding vrf_trans
 ip address 172.22.1.1 255.255.0.0
!
interface Ethernet1/0
 ip vrf forwarding vrf_user
 ip address 172.23.1.1 255.255.0.0
!
router bgp 45000
 no bgp default ipv4-unicast
 bgp log-neighbor-changes
 neighbor 192.168.3.1 remote-as 45000
 neighbor 192.168.3.1 update-source Loopback0
 !
 address-family vpnv4
  neighbor 192.168.3.1 activate
  neighbor 192.168.3.1 send-community extended
  exit-address-family
 !
 address-family ipv4 vrf vrf_user
  redistribute connected
  neighbor 172.22.1.1 remote-as 40000
  neighbor 172.22.1.1 local-as 50000 no-prepend
  neighbor 172.22.1.1 ebgp-multihop 2
  neighbor 172.22.1.1 activate
  neighbor 172.22.1.1 allowas-in 1
  no auto-summary
  no synchronization
  bgp router-id 10.99.1.1
  exit-address-family
 !
 address-family ipv4 vrf vrf_trans
  redistribute connected
  neighbor 172.23.1.1 remote-as 50000
  neighbor 172.23.1.1 local-as 40000 no-prepend
  neighbor 172.23.1.1 ebgp-multihop 2
  neighbor 172.23.1.1 activate
  neighbor 172.23.1.1 allowas-in 1
  no auto-summary
  no synchronization
  bgp router-id 10.99.1.2
  exit-address-family

          After the configuration, the output of the show ip bgp vpnv4 all command shows the router ID displayed next to the VRF name: 

          Router# show ip bgp vpnv4 all

BGP table version is 43, local router ID is 10.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
   Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 45000:1 (default for vrf vrf_trans) VRF Router ID 10.99.1.2
*> 172.22.0.0       0.0.0.0                  0         32768 ?
r> 172.23.0.0       172.23.1.1               0             0 3 1 ?
*>i10.21.1.1/32     192.168.3.1              0    100      0 2 i
*> 10.52.1.0/24     172.23.1.1                             0 3 1 ?
*> 10.52.2.1/32     172.23.1.1                             0 3 1 3 i
*> 10.52.3.1/32     172.23.1.1                             0 3 1 3 i
*> 10.99.1.1/32     172.23.1.1               0             0 3 1 ?
*> 10.99.2.2/32     0.0.0.0                  0         32768 ?
Route Distinguisher: 50000:1
*>i10.21.1.1/32     192.168.3.1              0    100      0 2 i
Route Distinguisher: 65500:1 (default for vrf vrf_user) VRF Router ID 10.99.1.1
r> 172.22.0.0       172.22.1.1               0             0 2 1 ?
*> 172.23.0.0       0.0.0.0                  0         32768 ?
*> 10.21.1.1/32     172.22.1.1                             0 2 1 2 i
*>i10.52.1.0/24     192.168.3.1              0    100      0 ?
*>i10.52.2.1/32     192.168.3.1              0    100      0 3 i
*>i10.52.3.1/32     192.168.3.1              0    100      0 3 i
*> 10.99.1.1/32     0.0.0.0                  0         32768 ?
*> 10.99.2.2/32     172.22.1.1               0             0 2 1 ?

          The output of the show ip bgp vpnv4 vrf command for a specified VRF displays the router ID in the output header: 

          Router# show ip bgp vpnv4 vrf vrf_user

BGP table version is 43, local router ID is 10.99.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
   Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 65500:1 (default for vrf vrf_user) VRF Router ID 10.99.1.1
r> 172.22.0.0       172.22.1.1               0             0 2 1 ?
*> 172.23.0.0       0.0.0.0                  0         32768 ?
*> 10.21.1.1/32     172.22.1.1                             0 2 1 2 i
*>i10.52.1.0/24     192.168.3.1              0    100      0 ?
*>i10.52.2.1/32     192.168.3.1              0    100      0 3 i
*>i10.52.3.1/32     192.168.3.1              0    100      0 3 i
*> 10.99.1.1/32     0.0.0.0                  0         32768 ?
*> 10.99.2.2/32     172.22.1.1               0             0 2 1 ?

          The output of the show ip bgp vpnv4 vrf summary command for a specified VRF displays the router ID in the first line of the output: 

          Router# show ip bgp vpnv4 vrf vrf_user summary

BGP router identifier 10.99.1.1, local AS number 45000
BGP table version is 43, main routing table version 43
8 network entries using 1128 bytes of memory
8 path entries using 544 bytes of memory
16/10 BGP path/bestpath attribute entries using 1856 bytes of memory
6 BGP AS-PATH entries using 144 bytes of memory
3 BGP extended community entries using 72 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 3744 total bytes of memory
BGP activity 17/0 prefixes, 17/0 paths, scan interval 15 secs
Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
172.22.1.1      4     2      20      21       43    0    0 00:12:33        3

          When the path is sourced in the VRF, the correct router ID is displayed in the output of the show ip bgp vpnv4 vrfcommand for a specified VRF and network address: 

          Router# show ip bgp vpnv4 vrf vrf_user 172.23.0.0

BGP routing table entry for 65500:1:172.23.0.0/8, version 22
Paths: (1 available, best #1, table vrf_user)
  Advertised to update-groups:
     2          3         
  Local
    0.0.0.0 from 0.0.0.0 (10.99.1.1)
      Origin incomplete, metric 0, localpref 100, weight 32768, valid, sourced, best
      Extended Community: RT:65500:1

          Example: Automatically Assigning a BGP Router ID per VRF

          The following three examples show different methods of configuring BGP to automatically assign a separate router ID to each VRF instance.

          Globally Automatically Assigned Router ID Using Loopback Interface IP Addresses

          The following example shows how to configure two VRFs—vrf_trans and vrf_user—with sessions between each other on the same router. Under router configuration mode, BGP is globally configured to automatically assign each VRF a BGP router ID. Loopback interfaces are associated with individual VRFs to source an IP address for the router ID. The show ip bgp vpnv4 command can be used to verify that the router IDs have been configured for each VRF. 

          ip vrf vrf_trans
 rd 45000:1
 route-target export 50000:50
 route-target import 40000:1
!
ip vrf vrf_user
 rd 65500:1
 route-target export 65500:1
 route-target import 65500:1
!
interface Loopback0
 ip address 10.1.1.1 255.255.255.255
!
interface Loopback1
 ip vrf forwarding vrf_user
 ip address 10.99.1.1 255.255.255.255
!
interface Loopback2
 ip vrf forwarding vrf_trans
 ip address 10.99.2.2 255.255.255.255
!
interface Ethernet0/0
 ip vrf forwarding vrf_trans
 ip address 172.22.1.1 255.0.0.0
!
interface Ethernet1/0
 ip vrf forwarding vrf_user
 ip address 172.23.1.1 255.0.0.0
!
router bgp 45000
 bgp router-id vrf auto-assign
 no bgp default ipv4-unicast
 bgp log-neighbor-changes
 neighbor 192.168.3.1 remote-as 45000
 neighbor 192.168.3.1 update-source Loopback0
 !
address-family vpnv4
  neighbor 192.168.3.1 activate
  neighbor 192.168.3.1 send-community extended
  exit-address-family
 !
 address-family ipv4 vrf vrf_user
  redistribute connected
  neighbor 172.22.1.1 remote-as 40000
  neighbor 172.22.1.1 local-as 50000 no-prepend
  neighbor 172.22.1.1 ebgp-multihop 2
  neighbor 172.22.1.1 activate
  neighbor 172.22.1.1 allowas-in 1
  no auto-summary
  no synchronization
  exit-address-family
 !
 address-family ipv4 vrf vrf_trans
  redistribute connected
  neighbor 172.23.1.1 remote-as 50000
  neighbor 172.23.1.1 local-as 2 no-prepend
  neighbor 172.23.1.1 ebgp-multihop 2
  neighbor 172.23.1.1 activate
  neighbor 172.23.1.1 allowas-in 1
  no auto-summary
  no synchronization
  exit-address-family

          After the configuration, the output of the show ip bgp vpnv4 all command shows the router ID displayed next to the VRF name. Note that the router IDs used in this example are sourced from the IP addresses configured for loopback interface 1 and loopback interface 2. The router IDs are the same as in the “Example: Manually Configurinig a BGP Router ID per VRF” section. 

          Router# show ip bgp vpnv4 all

BGP table version is 43, local router ID is 10.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
   Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 45000:1 (default for vrf vrf_trans) VRF Router ID 10.99.2.2
*> 172.22.0.0       0.0.0.0                  0         32768 ?
r> 172.23.0.0       172.23.1.1               0             0 3 1 ?
*>i10.21.1.1/32     192.168.3.1              0    100      0 2 i
*> 10.52.1.0/24     172.23.1.1                             0 3 1 ?
*> 10.52.2.1/32     172.23.1.1                             0 3 1 3 i
*> 10.52.3.1/32     172.23.1.1                             0 3 1 3 i
*> 10.99.1.1/32     172.23.1.1               0             0 3 1 ?
*> 10.99.1.2/32     0.0.0.0                  0         32768 ?
Route Distinguisher: 50000:1
*>i10.21.1.1/32     192.168.3.1              0    100      0 2 i
Route Distinguisher: 65500:1 (default for vrf vrf_user) VRF Router ID 10.99.1.1
r> 172.22.0.0       172.22.1.1               0             0 2 1 ?
*> 172.23.0.0       0.0.0.0                  0         32768 ?
*> 10.21.1.1/32     172.22.1.1                             0 2 1 2 i
*>i10.52.1.0/24     192.168.3.1              0    100      0 ?
*>i10.52.2.1/32     192.168.3.1              0    100      0 3 i
*>i10.52.3.1/32     192.168.3.1              0    100      0 3 i
*> 10.99.1.1/32     0.0.0.0                  0         32768 ?
*> 10.99.1.2/32     172.22.1.1               0             0 2 1 ?

          Globally Automatically Assigned Router ID with No Default Router ID

          The following example shows how to configure a router and associate a VRF that is automatically assigned a BGP router ID when no default router ID is allocated. 

          ip vrf vpn1
 rd 45000:1
 route-target export 45000:1
 route-target import 45000:1
!
interface Loopback0
 ip vrf forwarding vpn1
 ip address 10.1.1.1 255.255.255.255
!
interface Ethernet0/0
 ip vrf forwarding vpn1
 ip address 172.22.1.1 255.0.0.0
!
router bgp 45000
 bgp router-id vrf auto-assign
 no bgp default ipv4-unicast
 bgp log-neighbor-changes
 !
 address-family ipv4 vrf vpn1
  neighbor 172.22.1.2 remote-as 40000
  neighbor 172.22.1.2 activate
  no auto-summary
  no synchronization
  exit-address-family

          Assuming that a second router is configured to establish a session between the two routers, the output of the show ip interface brief command shows only the VRF interfaces that are configured. 

          Router# show ip interface brief

Interface              IP-Address      OK? Method Status                Protocol
Ethernet0/0            172.22.1.1      YES NVRAM  up                    up      
Ethernet1/0            unassigned      YES NVRAM  administratively down down    
Serial2/0              unassigned      YES NVRAM  administratively down down    
Serial3/0              unassigned      YES NVRAM  administratively down down    
Loopback0              10.1.1.1        YES NVRAM  up                    up

          The show ip vrf command can be used to verify that a router ID is assigned for the VRF: 

          Router# show ip vrf

Name                             Default RD          Interfaces
  vpn1                             45000:1             Loopback0
                                                       Ethernet0/0
VRF session is established:

          Per-VRF Automatically Assigned Router ID

          The following example shows how to configure two VRFs—vrf_trans and vrf_user—with sessions between each other on the same router. Under the IPv4 address family associated with an individual VRF, BGP is configured to automatically assign a BGP router ID. Loopback interfaces are associated with individual VRFs to source an IP address for the router ID. The output of the show ip bgp vpnv4 command can be used to verify that the router IDs have been configured for each VRF. 

          ip vrf vrf_trans
 rd 45000:1
 route-target export 50000:50
 route-target import 40000:1
!
ip vrf vrf_user
 rd 65500:1
 route-target export 65500:1
 route-target import 65500:1
!
interface Loopback0
 ip address 10.1.1.1 255.255.255.255
!
interface Loopback1
 ip vrf forwarding vrf_user
 ip address 10.99.1.1 255.255.255.255
!
interface Loopback2
 ip vrf forwarding vrf_trans
 ip address 10.99.2.2 255.255.255.255
!
interface Ethernet0/0
 ip vrf forwarding vrf_trans
 ip address 172.22.1.1 255.0.0.0
!
interface Ethernet1/0
 ip vrf forwarding vrf_user
 ip address 172.23.1.1 255.0.0.0
!
router bgp 45000
 no bgp default ipv4-unicast
 bgp log-neighbor-changes
 neighbor 192.168.3.1 remote-as 45000
 neighbor 192.168.3.1 update-source Loopback0
 !
address-family vpnv4
  neighbor 192.168.3.1 activate
  neighbor 192.168.3.1 send-community extended
  exit-address-family
!
 address-family ipv4 vrf vrf_user
  redistribute connected
  neighbor 172.22.1.1 remote-as 40000
  neighbor 172.22.1.1 local-as 50000 no-prepend
  neighbor 172.22.1.1 ebgp-multihop 2
  neighbor 172.22.1.1 activate
  neighbor 172.22.1.1 allowas-in 1
  no auto-summary
  no synchronization
  bgp router-id auto-assign
  exit-address-family
 !
 address-family ipv4 vrf vrf_trans
  redistribute connected
  neighbor 172.23.1.1 remote-as 50000
  neighbor 172.23.1.1 local-as 40000 no-prepend
  neighbor 172.23.1.1 ebgp-multihop 2
  neighbor 172.23.1.1 activate
  neighbor 172.23.1.1 allowas-in 1
  no auto-summary
  no synchronization
  bgp router-id auto-assign
  exit-address-family

          After the configuration, the output of the show ip bgp vpnv4 all command shows the router ID displayed next to the VRF name. Note that the router IDs used in this example are sourced from the IP addresses configured for loopback interface 1 and loopback interface 2. 

          Router# show ip bgp vpnv4 all

BGP table version is 43, local router ID is 10.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
   Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 45000:1 (default for vrf vrf_trans) VRF Router ID 10.99.2.2
*> 172.22.0.0       0.0.0.0                  0         32768 ?
r> 172.23.0.0       172.23.1.1               0             0 3 1 ?
*>i10.21.1.1/32     192.168.3.1              0    100      0 2 i
*> 10.52.1.0/24     172.23.1.1                             0 3 1 ?
*> 10.52.2.1/32     172.23.1.1                             0 3 1 3 i
*> 10.52.3.1/32     172.23.1.1                             0 3 1 3 i
*> 10.99.1.1/32     172.23.1.1               0             0 3 1 ?
*> 10.99.1.2/32     0.0.0.0                  0         32768 ?
Route Distinguisher: 50000:1
*>i10.21.1.1/32     192.168.3.1              0    100      0 2 i
Route Distinguisher: 65500:1 (default for vrf vrf_user) VRF Router ID 10.99.1.1
r> 172.22.0.0       172.22.1.1               0             0 2 1 ?
*> 172.23.0.0       0.0.0.0                  0         32768 ?
*> 10.21.1.1/32     172.22.1.1                             0 2 1 2 i
*>i10.52.1.0/24     192.168.3.1              0    100      0 ?
*>i10.52.2.1/32     192.168.3.1              0    100      0 3 i
*>i10.52.3.1/32     192.168.3.1              0    100      0 3 i
*> 10.99.1.1/32     0.0.0.0                  0         32768 ?
*> 10.99.1.2/32     172.22.1.1               0             0 2 1 ?

          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

          MPLS commands

          Cisco IOS Multiprotocol Label Switching Command Reference

          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

          —

          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

          No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature.

          —

          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 Per-VRF Assignment of BGP Router ID

          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 . An account on Cisco.com is not required.
          Table 1 Feature Information for Per-VRF Assignment of BGP Router ID

          Feature Name

          Releases

          Feature Information

          Per-VRF Assignment of BGP Router ID

          12.2(31)SB2

          12.2(33)SRA

          12.2(33)SXH

          12.4(20)T

          15.0(1)S

          The Per-VRF Assignment of BGP Router ID feature introduces the ability to have VRF-to-VRF peering in Border Gateway Protocol (BGP) on the same router. BGP is designed to refuse a session with itself because of the router ID check. The per-VRF assignment feature allows a separate router ID per VRF using a new keyword in the existing bgp router-id command. The router ID can be manually configured for each VRF or can be assigned automatically either globally under address family configuration mode or for each VRF.

          The following commands were introduced or modified by this feature: bgp router-id, show ip bgp vpnv4.

          Per-VRF Assignment of BGP Router ID

          Per-VRF Assignment of BGP Router ID

          The Per-VRF Assignment of BGP Router ID feature introduces the ability to have VRF-to-VRF peering in Border Gateway Protocol (BGP) on the same router. BGP is designed to refuse a session with itself because of the router ID check. The per-VRF assignment feature allows a separate router ID per VRF using a new keyword in the existing bgp router-id command. The router ID can be manually configured for each VRF or can be assigned automatically either globally under address family configuration mode or for each VRF.

          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 Per-VRF Assignment of BGP Router ID

          Before you configure this feature, Cisco Express Forwarding (CEF) or distributed CEF (dCEF) must be enabled in the network, and basic BGP peering is assumed to be running in the network.

          Information About Per-VRF Assignment of BGP Router ID

          BGP Router ID

          The BGP router identifier (ID) is a 4-byte field that is set to the highest IP address on the router. Loopback interface addresses are considered before physical interface addresses because loopback interfaces are more stable than physical interfaces. The BGP router ID is used in the BGP algorithm for determining the best path to a destination where the preference is for the BGP router with the lowest router ID. It is possible to manually configure the BGP router ID using the bgp router-id command to influence the best path algorithm.

          Per-VRF Router ID Assignment

          The Per-VRF Assignment of BGP Router ID feature introduces the ability to have VRF-to-VRF peering in Border Gateway Protocol (BGP) on the same router. BGP is designed to refuse a session with itself because of the router ID check. The Per-VRF Assignment of BGP Router ID feature allows a separate router ID per VRF using a new keyword in the existing bgp router-id command. The router ID can be manually configured for each VRF or can be assigned automatically either globally under address family configuration mode or for each VRF.

          Route Distinguisher

          A route distinguisher (RD) creates routing and forwarding tables and specifies the default route distinguisher for a VPN. The RD is added to the beginning of an IPv4 prefix to change it into a globally unique VPN-IPv4 prefix. An RD can be composed in one of two ways: with an autonomous system number and an arbitrary number or with an IP address and an arbitrary number.

          You can enter an RD in either of these formats:

          • Enter a 16-bit autonomous system number, a colon, and a 32-bit number. For example:

          45000:3

          • Enter a 32-bit IP address, a colon, and a 16-bit number. For example:

          192.168.10.15:1

          How to Configure Per-VRF Assignment of BGP Router ID

          Configuring VRF Instances

          Perform this task to configure VRF instances to be used with the Per-VRF Assignment of Router ID tasks. In this task, a VRF instance named vrf_trans is created. To make the VRF functional, a route distinguisher is created. When the route distinguisher is created, the routing and forwarding tables are created for the VRF instance named vrf_trans.

          Before You Begin

          This task assumes that you have CEF or dCEF enabled.

          SUMMARY STEPS

            1.    enable

            2.    configure terminal

            3.    ip vrf vrf-name

            4.    rd route-distinguisher

            5.    route-target [import | both] route-target-ext-community

            6.    route-target [export | both] route-target-ext-community

            7.    exit

            8.    Repeat Step 3 through Step 7 for each VRF to be defined.


          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 ip vrf vrf-name


            Example:
            Device(config)# ip vrf vrf_trans
             

            Defines a VRF instance and enters VRF configuration mode.

             
            Step 4 rd route-distinguisher


            Example:
            Device(config-vrf)# rd 45000:2
             

            Creates routing and forwarding tables for a VRF and specifies the default RD for a VPN.

            • Use the route-distinguisher argument to specify the default RD for a VPN. There are two formats you can use to specify an RD. For more details, see the “Route Distinguisher” section.

            • In this example, the RD uses an autonomous system number with the number 2 after the colon.

             
            Step 5 route-target [import | both] route-target-ext-community


            Example:
            Device(config-vrf)# route-target import 55000:5
             

            Creates a route-target extended community for a VRF.

            • Use the import keyword to import routing information from the target VPN extended community.

            • Use the both keyword to both import routing information from and export routing information to the target VPN extended community.

            • Use the route-target-ext-community argument to specify the VPN extended community.

             
            Step 6 route-target [export | both] route-target-ext-community


            Example:
            Device(config-vrf)# route-target export 55000:1
             

            Creates a route-target extended community for a VRF.

            • Use the export keyword to export routing information to the target VPN extended community.

            • Use the both keyword to both import routing information from and export routing information to the target VPN extended community.

            • Use the route-target-ext-community argument to specify the VPN extended community.

             
            Step 7 exit


            Example:
            Device(config-vrf)# exit
             

            Exits VRF configuration mode and returns to global configuration mode.

             
            Step 8 Repeat Step 3 through Step 7 for each VRF to be defined.  

             

            Associating VRF Instances with Interfaces

            Perform this task to associate VRF instances with interfaces to be used with the per-VRF assignment tasks. In this task, a VRF instance named vrf_trans is associated with a serial interface.

            Make a note of the IP addresses for any interface to which you want to associate a VRF instance because the ip vrf forwarding command removes the IP address. Step 8 allows you to reconfigure the IP address.

            Before You Begin

            • This task assumes that you have CEF or dCEF enabled.

            • This task assumes that VRF instances have been configured as shown in preceding “Configuring VRF Instances” task in this module.

            SUMMARY STEPS

              1.    enable

              2.    configure terminal

              3.    interface type number

              4.    ip address ip-address mask [secondary]

              5.    exit

              6.    interface type number

              7.    ip vrf forwarding vrf-name [downstream vrf-name2]

              8.    ip address ip-address mask [secondary]

              9.    Repeat Step 5 through Step 8 for each VRF to be associated with an interface.

              10.    end

              11.    show ip vrf [brief | detail | interfaces | id] [vrf-name]


            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 interface type number


              Example:
              Router(config)# interface loopback0
               

              Configures an interface type and enters interface configuration mode.

              • In this example, loopback interface 0 is configured.

               
              Step 4 ip address ip-address mask [secondary]


              Example:
              Router(config-if)# ip address 172.16.1.1 255.255.255.255
               

              Configures an IP address.

              • In this example, the loopback interface is configured with an IP address of 172.16.1.1.

               
              Step 5 exit


              Example:
              Router(config-if)# exit
               

              Exits interface configuration mode and returns to global configuration mode.

               
              Step 6 interface type number


              Example:
              Router(config)# interface serial2/0
               

              Configures an interface type and enters interface configuration mode.

              • In this example, serial interface 2/0 is configured.

               
              Step 7 ip vrf forwarding vrf-name [downstream vrf-name2]


              Example:
              Router(config-if)# ip vrf forwarding vrf_trans
               

              Associates a VRF with an interface or subinterface.

              • In this example, the VRF named vrf_trans is associated with serial interface 2/0.

              Note   

              Executing this command on an interface removes the IP address. The IP address should be reconfigured.

               
              Step 8 ip address ip-address mask [secondary]


              Example:
              Router(config-if)# ip address 192.168.4.1 255.255.255.0
               

              Configures an IP address.

              • In this example, serial interface 2/0 is configured with an IP address of 192.168.4.1.

               
              Step 9 Repeat Step 5 through Step 8 for each VRF to be associated with an interface.  

              --

               
              Step 10 end


              Example:
              Router(config-if)# end
               

              Exits interface configuration mode and returns to privileged EXEC mode.

               
              Step 11 show ip vrf [brief | detail | interfaces | id] [vrf-name]

              Example:
              Router# show ip vrf interfaces
               

              (Optional) Displays the set of defined VRFs and associated interfaces.

              • In this example, the output from this command shows the VRFs that have been created and their associated interfaces.

               

              Examples

              The following output show s that two VRF instances named vrf_trans and vrf_users were configured on two serial interfaces. 

              Router# show ip vrf interfaces

Interface         IP-Address      VRF                      Protocol
Serial2           192.168.4.1     vrf_trans                up      
Serial3           192.168.5.1     vrf_user                 up

              Manually Configuring a BGP Router ID per VRF

              Perform this task to manually configure a BGP router ID for each VRF. In this task, several address family configurations are shown and the router ID is configured in the IPv4 address family mode for one VRF instance. Step 22 shows you how to repeat certain steps to permit the configuration of more than one VRF on the same router.

              Before You Begin

              This task assumes that you have previously created the VRF instances and associated them with interfaces. For more details, see the “Configuring VRF Instances” task and the “Associating VRF Instances with Interfaces” task earlier in this module.

              SUMMARY STEPS

                1.    enable

                2.    configure terminal

                3.    router bgp autonomous-system-number

                4.    no bgp default ipv4-unicast

                5.    bgp log-neighbor-changes

                6.    neighbor {ip-address | peer-group-name} remote-as autonomous-system-number

                7.    neighbor {ip-address | peer-group-name} update-source interface-type interface-number

                8.    address-family {ipv4 [mdt | multicast | unicast [vrf vrf-name] | vrf vrf-name] | vpnv4 [unicast]}

                9.    neighbor {ip-address | peer-group-name} activate

                10.    neighbor {ip-address | peer-group-name} send-community {both | standard | extended}

                11.    exit-address-family

                12.    address-family {ipv4 [mdt | multicast | unicast [vrf vrf-name] | vrf vrf-name] | vpnv4 [unicast]}

                13.    redistribute connected

                14.    neighbor {ip-address | peer-group-name} remote-as autonomous-system-number

                15.    neighbor ip-address local-as autonomous-system-number [no-prepend [replace-as [dual-as]]]

                16.    neighbor {ip-address | peer-group-name} ebgp-multihop [ttl]

                17.    neighbor {ip-address | peer-group-name} activate

                18.    neighbor ip-address allowas-in [number]

                19.    no auto-summary

                20.    no synchronization

                21.    bgp router-id {ip-address | auto-assign}

                22.    Repeat Step 11 to Step 21 to configure another VRF instance.

                23.    end

                24.    show ip bgp vpnv4 {all | rd route-distinguisher | vrf vrf-name}


              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 bgp autonomous-system-number


                Example:
                Router(config)# router bgp 45000
                 

                Enters router configuration mode for the specified routing process.

                 
                Step 4 no bgp default ipv4-unicast


                Example:
                Router(config-router)# no bgp default ipv4-unicast
                 

                Disables the IPv4 unicast address family for the BGP routing process.

                Note   

                Routing information for the IPv4 unicast address family is advertised by default for each BGP routing session configured with the neighbor remote-as router configuration command unless you configure the no bgp default ipv4-unicast router configuration command before configuring the neighbor remote-as command. Existing neighbor configurations are not affected.

                 
                Step 5 bgp log-neighbor-changes


                Example:
                Router(config-router)# bgp log-neighbor-changes
                 

                Enables logging of BGP neighbor resets.

                 
                Step 6 neighbor {ip-address | peer-group-name} remote-as autonomous-system-number


                Example:
                Router(config-router)# neighbor 192.168.1.1 remote-as 45000
                 

                Adds the IP address or peer group name of the neighbor in the specified autonomous system to the IPv4 multiprotocol BGP neighbor table of the local router.

                • If the autonomous-system-number argument matches the autonomous system number specified in the router bgp command, the neighbor is an internal neighbor.

                • If the autonomous-system-number argument does not match the autonomous system number specified in the router bgp command, the neighbor is an external neighbor.

                • In this example, the neighbor is an internal neighbor.

                 
                Step 7 neighbor {ip-address | peer-group-name} update-source interface-type interface-number


                Example:
                Router(config-router)# neighbor 192.168.1.1 update-source loopback0
                 

                Allows BGP sessions to use any operational interface for TCP connections.

                • In this example, BGP TCP connections for the specified neighbor are sourced with the IP address of the loopback interface rather than the best local address.

                 
                Step 8 address-family {ipv4 [mdt | multicast | unicast [vrf vrf-name] | vrf vrf-name] | vpnv4 [unicast]}


                Example:
                Router(config-router)# address-family vpnv4
                 

                Enters address family configuration mode to configure BGP peers to accept address-family-specific configurations.

                • The example creates a VPNv4 address family session.

                 
                Step 9 neighbor {ip-address | peer-group-name} activate


                Example:
                Router(config-router-af)# neighbor 172.16.1.1 activate
                 

                Activates the neighbor under the VPNv4 address family.

                • In this example, the neighbor 172.16.1.1 is activated.

                 
                Step 10 neighbor {ip-address | peer-group-name} send-community {both | standard | extended}


                Example:
                Router(config-router-af)# neighbor 172.16.1.1 send-community extended
                 

                Specifies that a communities attribute should be sent to a BGP neighbor.

                • In this example, an extended communities attribute is sent to the neighbor at 172.16.1.1.

                 
                Step 11 exit-address-family


                Example:
                Router(config-router-af)# exit-address-family
                 

                Exits address family configuration mode and returns to router configuration mode.

                 
                Step 12 address-family {ipv4 [mdt | multicast | unicast [vrf vrf-name] | vrf vrf-name] | vpnv4 [unicast]}


                Example:
                Router(config-router)# address-family ipv4 vrf vrf_trans
                 

                Enters address family configuration mode to configure BGP peers to accept address-family-specific configurations.

                • The example specifies that the VRF instance named vrf_trans is to be associated with subsequent IPv4 address family configuration commands.

                 
                Step 13 redistribute connected


                Example:
                Router(config-router-af)# redistribute connected
                 

                Redistributes from one routing domain into another routing domain.

                • In this example, the connected keyword is used to represent routes that are established automatically when IP is enabled on an interface.

                • Only the syntax applicable to this step is displayed. For more details, see the Cisco IOS IP Routing: BGP Command Reference.

                 
                Step 14 neighbor {ip-address | peer-group-name} remote-as autonomous-system-number


                Example:
                Router(config-router-af)# neighbor 192.168.1.1 remote-as 40000
                 

                Adds the IP address or peer group name of the neighbor in the specified autonomous system to the IPv4 multiprotocol BGP neighbor table of the local router.

                • If the autonomous-system-number argument matches the autonomous system number specified in the router bgp command, the neighbor is an internal neighbor.

                • If the autonomous-system-number argument does not match the autonomous system number specified in the router bgp command, the neighbor is an external neighbor.

                • In this example, the neighbor at 192.168.1.1 is an external neighbor.

                 
                Step 15 neighbor ip-address local-as autonomous-system-number [no-prepend [replace-as [dual-as]]]


                Example:
                Router(config-router-af)# neighbor 192.168.1.1 local-as 50000 no-prepend
                 

                Customizes the AS_PATH attribute for routes received from an eBGP neighbor.

                • The autonomous system number from the local BGP routing process is prepended to all external routes by default.

                • Use the no-prepend keyword to not prepend the local autonomous system number to any routes received from the eBGP neighbor.

                • In this example, routes from the neighbor at 192.168.1.1 will not contain the local autonomous system number.

                 
                Step 16 neighbor {ip-address | peer-group-name} ebgp-multihop [ttl]


                Example:
                Router(config-router-af)# neighbor 192.168.1.1 ebgp-multihop 2
                 

                Accepts and attempts BGP connections to external peers residing on networks that are not directly connected.

                • In this example, BGP is configured to allow connections to or from neighbor 192.168.1.1, which resides on a network that is not directly connected.

                 
                Step 17 neighbor {ip-address | peer-group-name} activate


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

                Activates the neighbor under the IPV4 address family.

                • In this example, the neighbor 192.168.1.1 is activated.

                 
                Step 18 neighbor ip-address allowas-in [number]


                Example:
                Router(config-router-af)# neighbor 192.168.1.1 allowas-in 1
                 

                Configures provider edge (PE) routers to allow the readvertisement of all prefixes that contain duplicate autonomous system numbers.

                • In the example, the PE router with autonomous system number 45000 is configured to allow prefixes from the VRF vrf-trans. The neighboring PE router with the IP address 192.168.1.1 is set to be readvertised once to other PE routers with the same autonomous system number.

                 
                Step 19 no auto-summary


                Example:
                Router(config-router-af)# no auto-summary
                 

                Disables automatic summarization and sends subprefix routing information across classful network boundaries.

                 
                Step 20 no synchronization


                Example:
                Router(config-router-af)# no synchronization
                 

                Enables the Cisco IOS software to advertise a network route without waiting for synchronization with an Internal Gateway Protocol (IGP).

                 
                Step 21 bgp router-id {ip-address | auto-assign}


                Example:
                Router(config-router-af)# bgp router-id 10.99.1.1
                 

                Configures a fixed router ID for the local BGP routing process.

                • In this example, the specified BGP router ID is assigned for the VRF instance associated with this IPv4 address family configuration.

                 
                Step 22 Repeat Step 11 to Step 21 to configure another VRF instance.  

                --

                 
                Step 23 end


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

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

                 
                Step 24 show ip bgp vpnv4 {all | rd route-distinguisher | vrf vrf-name}


                Example:
                Router# show ip bgp vpnv4 all
                 

                (Optional) Displays VPN address information from the BGP table.

                • In this example, the complete VPNv4 database is displayed.

                Note   

                Only the syntax applicable to this task is used in this example. For more details, see the Cisco IOS Multiprotocol Label Switching Command Reference.

                 

                Examples

                The following sample output assumes that two VRF instances named vrf_trans and vrf_user were configured each with a separate router ID. The router ID is shown next to the VRF name. 

                Router# show ip bgp vpnv4 all

BGP table version is 5, local router ID is 172.17.1.99
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
   Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 1:1 (default for vrf vrf_trans) VRF Router ID 10.99.1.2
*> 192.168.4.0      0.0.0.0                  0         32768 ?
Route Distinguisher: 42:1 (default for vrf vrf_user) VRF Router ID 10.99.1.1
*> 192.168.5.0      0.0.0.0                  0         32768 ?

                Automatically Assigning a BGP Router ID per VRF

                Perform this task to automatically assign a BGP router ID for each VRF. In this task, a loopback interface is associated with a VRF and the bgp router-id command is configured at the router configuration level to automatically assign a BGP router ID to all VRF instances. Step 9 shows you how to repeat certain steps to configure each VRF that is to be associated with an interface. Step 30 shows you how to configure more than one VRF on the same router.

                Before You Begin

                This task assumes that you have previously created the VRF instances as shown in the “Configuring VRF Instances” task in this module.

                SUMMARY STEPS

                  1.    enable

                  2.    configure terminal

                  3.    interface type number

                  4.    ip address ip-address mask [secondary]

                  5.    exit

                  6.    interface type number

                  7.    ip vrf forwarding vrf-name [downstream vrf-name2]

                  8.    ip address ip-address mask [secondary]

                  9.    Repeat Step 5 through Step 8 for each VRF to be associated with an interface.

                  10.    exit

                  11.    router bgp autonomous-system-number

                  12.    bgp router-id {ip-address | vrf auto-assign}

                  13.    no bgp default ipv4-unicast

                  14.    bgp log-neighbor-changes

                  15.    neighbor {ip-address | peer-group-name} remote-as autonomous-system-number

                  16.    neighbor {ip-address | peer-group-name} update-source interface-type interface-number

                  17.    address-family {ipv4 [mdt | multicast | unicast [vrf vrf-name] | vrf vrf-name] | vpnv4 [unicast]}

                  18.    neighbor {ip-address | peer-group-name} activate

                  19.    neighbor {ip-address | peer-group-name} send-community {both | standard | extended}

                  20.    exit-address-family

                  21.    address-family {ipv4 [mdt | multicast | unicast [vrf vrf-name] | vrf vrf-name] | vpnv4 [unicast]}

                  22.    redistribute connected

                  23.    neighbor {ip-address | peer-group-name} remote-as autonomous-system-number

                  24.    neighbor ip-address local-as autonomous-system-number [no-prepend [replace-as [dual-as]]]

                  25.    neighbor {ip-address | peer-group-name} ebgp-multihop [ttl]

                  26.    neighbor {ip-address | peer-group-name} activate

                  27.    neighbor ip-address allowas-in [number]

                  28.    no auto-summary

                  29.    no synchronization

                  30.    Repeat Step 20 to Step 29 to configure another VRF instance.

                  31.    end

                  32.    show ip bgp vpnv4 {all | rd route-distinguisher | vrf vrf-name}


                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 interface type number


                  Example:
                  Router(config)# interface loopback0
                   

                  Configures an interface type and enters interface configuration mode.

                  • In this example, loopback interface 0 is configured.

                   
                  Step 4 ip address ip-address mask [secondary]


                  Example:
                  Router(config-if)# ip address 172.16.1.1 255.255.255.255
                   

                  Configures an IP address.

                  • In this example, the loopback interface is configured with an IP address of 172.16.1.1.

                   
                  Step 5 exit


                  Example:
                  Router(config-if)# exit
                   

                  Exits interface configuration mode and returns to global configuration mode.

                   
                  Step 6 interface type number


                  Example:
                  Router(config)# interface loopback1
                   

                  Configures an interface type and enters interface configuration mode.

                  • In this example, loopback interface 1 is configured.

                   
                  Step 7 ip vrf forwarding vrf-name [downstream vrf-name2]


                  Example:
                  Router(config-if)# ip vrf forwarding vrf_trans
                   

                  Associates a VRF with an interface or subinterface.

                  • In this example, the VRF named vrf_trans is associated with loopback interface 1.

                  Note   

                  Executing this command on an interface removes the IP address. The IP address should be reconfigured.

                   
                  Step 8 ip address ip-address mask [secondary]


                  Example:
                  Router(config-if)# ip address 10.99.1.1 255.255.255.255
                   

                  Configures an IP address.

                  • In this example, loopback interface 1 is configured with an IP address of 10.99.1.1.

                   
                  Step 9 Repeat Step 5 through Step 8 for each VRF to be associated with an interface.  

                  --

                   
                  Step 10 exit


                  Example:
                  Router(config-if)# exit
                   

                  Exits interface configuration mode and returns to global configuration mode.

                   
                  Step 11 router bgp autonomous-system-number


                  Example:
                  Router(config)# router bgp 45000
                   

                  Enters router configuration mode for the specified routing process.

                   
                  Step 12 bgp router-id {ip-address | vrf auto-assign}


                  Example:
                  Router(config-router)# bgp router-id vrf auto-assign
                   

                  Configures a fixed router ID for the local BGP routing process.

                  • In this example, a BGP router ID is automatically assigned for each VRF instance.

                   
                  Step 13 no bgp default ipv4-unicast


                  Example:
                  Router(config-router)# no bgp default ipv4-unicast
                   

                  Disables the IPv4 unicast address family for the BGP routing process.

                  Note   

                  Routing information for the IPv4 unicast address family is advertised by default for each BGP routing session configured with the neighbor remote-as router configuration command unless you configure the no bgp default ipv4-unicast router configuration command before configuring the neighbor remote-as command. Existing neighbor configurations are not affected.

                   
                  Step 14 bgp log-neighbor-changes


                  Example:
                  Router(config-router)# bgp log-neighbor-changes
                   

                  Enables logging of BGP neighbor resets.

                   
                  Step 15 neighbor {ip-address | peer-group-name} remote-as autonomous-system-number


                  Example:
                  Router(config-router)# neighbor 192.168.1.1 remote-as 45000
                   

                  Adds the IP address or peer group name of the neighbor in the specified autonomous system to the IPv4 multiprotocol BGP neighbor table of the local router.

                  • If the autonomous-system-number argument matches the autonomous system number specified in the router bgp command, the neighbor is an internal neighbor.

                  • If the autonomous-system-number argument does not match the autonomous system number specified in the router bgp command, the neighbor is an external neighbor.

                  • In this example, the neighbor is an internal neighbor.

                   
                  Step 16 neighbor {ip-address | peer-group-name} update-source interface-type interface-number


                  Example:
                  Router(config-router)# neighbor 192.168.1.1 update-source loopback0
                   

                  Allows BGP sessions to use any operational interface for TCP connections.

                  • In this example, BGP TCP connections for the specified neighbor are sourced with the IP address of the loopback interface rather than the best local address.

                   
                  Step 17 address-family {ipv4 [mdt | multicast | unicast [vrf vrf-name] | vrf vrf-name] | vpnv4 [unicast]}


                  Example:
                  Router(config-router)# address-family vpnv4
                   

                  Enters address family configuration mode to configure BGP peers to accept address-family-specific configurations.

                  • The example creates a VPNv4 address family session.

                   
                  Step 18 neighbor {ip-address | peer-group-name} activate


                  Example:
                  Router(config-router-af)# neighbor 172.16.1.1 activate
                   

                  Activates the neighbor under the VPNv4 address family.

                  • In this example, the neighbor 172.16.1.1 is activated.

                   
                  Step 19 neighbor {ip-address | peer-group-name} send-community {both | standard | extended}


                  Example:
                  Router(config-router-af)# neighbor 172.16.1.1 send-community extended
                   

                  Specifies that a communities attribute should be sent to a BGP neighbor.

                  • In this example, an extended communities attribute is sent to the neighbor at 172.16.1.1.

                   
                  Step 20 exit-address-family


                  Example:
                  Router(config-router-af)# exit-address-family
                   

                  Exits address family configuration mode and returns to router configuration mode.

                   
                  Step 21 address-family {ipv4 [mdt | multicast | unicast [vrf vrf-name] | vrf vrf-name] | vpnv4 [unicast]}


                  Example:
                  Router(config-router)# address-family ipv4 vrf vrf_trans
                   

                  Enters address family configuration mode to configure BGP peers to accept address-family-specific configurations.

                  • The example specifies that the VRF instance named vrf_trans is to be associated with subsequent IPv4 address family configuration mode commands.

                   
                  Step 22 redistribute connected


                  Example:
                  Router(config-router-af)# redistribute connected
                   

                  Redistributes from one routing domain into another routing domain.

                  • In this example, the connected keyword is used to represent routes that are established automatically when IP is enabled on an interface.

                  • Only the syntax applicable to this step is displayed. For more details, see the Cisco IOS IP Routing: BGP Command Reference.

                   
                  Step 23 neighbor {ip-address | peer-group-name} remote-as autonomous-system-number


                  Example:
                  Router(config-router-af)# neighbor 192.168.1.1 remote-as 40000
                   

                  Adds the IP address or peer group name of the neighbor in the specified autonomous system to the IPv4 multiprotocol BGP neighbor table of the local router.

                  • If the autonomous-system-number argument matches the autonomous system number specified in the router bgp command, the neighbor is an internal neighbor.

                  • If the autonomous-system-number argument does not match the autonomous system number specified in the router bgp command, the neighbor is an external neighbor.

                  • In this example, the neighbor at 192.168.1.1 is an external neighbor.

                   
                  Step 24 neighbor ip-address local-as autonomous-system-number [no-prepend [replace-as [dual-as]]]


                  Example:
                  Router(config-router-af)# neighbor 192.168.1.1 local-as 50000 no-prepend
                   

                  Customizes the AS_PATH attribute for routes received from an eBGP neighbor.

                  • The autonomous system number from the local BGP routing process is prepended to all external routes by default.

                  • Use the no-prepend keyword to not prepend the local autonomous system number to any routes received from the eBGP neighbor.

                  • In this example, routes from the neighbor at 192.168.1.1 will not contain the local autonomous system number.

                   
                  Step 25 neighbor {ip-address | peer-group-name} ebgp-multihop [ttl]


                  Example:
                  Router(config-router-af)# neighbor 192.168.1.1 ebgp-multihop 2
                   

                  Accepts and attempts BGP connections to external peers residing on networks that are not directly connected.

                  • In this example, BGP is configured to allow connections to or from neighbor 192.168.1.1, which resides on a network that is not directly connected.

                   
                  Step 26 neighbor {ip-address | peer-group-name} activate


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

                  Activates the neighbor under the IPV4 address family.

                  • In this example, the neighbor 192.168.1.1 is activated.

                   
                  Step 27 neighbor ip-address allowas-in [number]


                  Example:
                  Router(config-router-af)# neighbor 192.168.1.1 allowas-in 1
                   

                  Configures provider edge (PE) routers to allow the readvertisement of all prefixes that contain duplicate autonomous system numbers.

                  • In the example, the PE router with autonomous system number 45000 is configured to allow prefixes from the VRF vrf-trans. The neighboring PE router with the IP address 192.168.1.1 is set to be readvertised once to other PE routers with the same autonomous system number.

                   
                  Step 28 no auto-summary


                  Example:
                  Router(config-router-af)# no auto-summary
                   

                  Disables automatic summarization and sends subprefix routing information across classful network boundaries.

                   
                  Step 29 no synchronization


                  Example:
                  Router(config-router-af)# no synchronization
                   

                  Enables the Cisco IOS software to advertise a network route without waiting for synchronization with an Internal Gateway Protocol (IGP).

                   
                  Step 30 Repeat Step 20 to Step 29 to configure another VRF instance.  

                  --

                   
                  Step 31 end


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

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

                   
                  Step 32 show ip bgp vpnv4 {all | rd route-distinguisher | vrf vrf-name}


                  Example:
                  Router# show ip bgp vpnv4 all
                   

                  (Optional) Displays VPN address information from the BGP table.

                  • In this example, the complete VPNv4 database is displayed.

                  Note   

                  Only the syntax applicable to this task is used in this example. For more details, see the Cisco IOS Multiprotocol Label Switching Command Reference.

                   

                  Examples

                  The following sample output assumes that two VRF instances named vrf_trans and vrf_user were configured, each with a separate router ID. The router ID is shown next to the VRF name. 

                  Router# show ip bgp vpnv4 all

BGP table version is 43, local router ID is 172.16.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
   Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 1:1 (default for vrf vrf_trans) VRF Router ID 10.99.1.2
*> 172.22.0.0       0.0.0.0                  0         32768 ?
r> 172.23.0.0       172.23.1.1               0             0 3 1 ?
*>i10.21.1.1/32     192.168.3.1              0    100      0 2 i
*> 10.52.1.0/24     172.23.1.1                             0 3 1 ?
*> 10.52.2.1/32     172.23.1.1                             0 3 1 3 i
*> 10.52.3.1/32     172.23.1.1                             0 3 1 3 i
*> 10.99.1.1/32     172.23.1.1               0             0 3 1 ?
*> 10.99.1.2/32     0.0.0.0                  0         32768 ?
Route Distinguisher: 10:1
*>i10.21.1.1/32     192.168.3.1              0    100      0 2 i
Route Distinguisher: 42:1 (default for vrf vrf_user) VRF Router ID 10.99.1.1
r> 172.22.0.0       172.22.1.1               0             0 2 1 ?
*> 172.23.0.0       0.0.0.0                  0         32768 ?
*> 10.21.1.1/32     172.22.1.1                             0 2 1 2 i
*>i10.52.1.0/24     192.168.3.1              0    100      0 ?
*>i10.52.2.1/32     192.168.3.1              0    100      0 3 i
*>i10.52.3.1/32     192.168.3.1              0    100      0 3 i
*> 10.99.1.1/32     0.0.0.0                  0         32768 ?
*> 10.99.1.2/32     172.22.1.1               0             0 2 1 ?

                  Configuration Examples for Per-VRF Assignment of BGP Router ID

                  Example: Manually Configuring a BGP Router ID per VRF

                  The following example shows how to configure two VRFs—vrf_trans and vrf_user—with sessions between each other on the same router. The BGP router ID for each VRF is configured manually under separate IPv4 address families. The show ip bgp vpnv4 command can be used to verify that the router IDs have been configured for each VRF. The configuration starts in global configuration mode. 

                  ip vrf vrf_trans
 rd 45000:1
 route-target export 50000:50
 route-target import 40000:1
!
ip vrf vrf_user
 rd 65500:1
 route-target export 65500:1
 route-target import 65500:1
!
interface Loopback0
 ip address 10.1.1.1 255.255.255.255
!
interface Ethernet0/0
 ip vrf forwarding vrf_trans
 ip address 172.22.1.1 255.255.0.0
!
interface Ethernet1/0
 ip vrf forwarding vrf_user
 ip address 172.23.1.1 255.255.0.0
!
router bgp 45000
 no bgp default ipv4-unicast
 bgp log-neighbor-changes
 neighbor 192.168.3.1 remote-as 45000
 neighbor 192.168.3.1 update-source Loopback0
 !
 address-family vpnv4
  neighbor 192.168.3.1 activate
  neighbor 192.168.3.1 send-community extended
  exit-address-family
 !
 address-family ipv4 vrf vrf_user
  redistribute connected
  neighbor 172.22.1.1 remote-as 40000
  neighbor 172.22.1.1 local-as 50000 no-prepend
  neighbor 172.22.1.1 ebgp-multihop 2
  neighbor 172.22.1.1 activate
  neighbor 172.22.1.1 allowas-in 1
  no auto-summary
  no synchronization
  bgp router-id 10.99.1.1
  exit-address-family
 !
 address-family ipv4 vrf vrf_trans
  redistribute connected
  neighbor 172.23.1.1 remote-as 50000
  neighbor 172.23.1.1 local-as 40000 no-prepend
  neighbor 172.23.1.1 ebgp-multihop 2
  neighbor 172.23.1.1 activate
  neighbor 172.23.1.1 allowas-in 1
  no auto-summary
  no synchronization
  bgp router-id 10.99.1.2
  exit-address-family

                  After the configuration, the output of the show ip bgp vpnv4 all command shows the router ID displayed next to the VRF name: 

                  Router# show ip bgp vpnv4 all

BGP table version is 43, local router ID is 10.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
   Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 45000:1 (default for vrf vrf_trans) VRF Router ID 10.99.1.2
*> 172.22.0.0       0.0.0.0                  0         32768 ?
r> 172.23.0.0       172.23.1.1               0             0 3 1 ?
*>i10.21.1.1/32     192.168.3.1              0    100      0 2 i
*> 10.52.1.0/24     172.23.1.1                             0 3 1 ?
*> 10.52.2.1/32     172.23.1.1                             0 3 1 3 i
*> 10.52.3.1/32     172.23.1.1                             0 3 1 3 i
*> 10.99.1.1/32     172.23.1.1               0             0 3 1 ?
*> 10.99.2.2/32     0.0.0.0                  0         32768 ?
Route Distinguisher: 50000:1
*>i10.21.1.1/32     192.168.3.1              0    100      0 2 i
Route Distinguisher: 65500:1 (default for vrf vrf_user) VRF Router ID 10.99.1.1
r> 172.22.0.0       172.22.1.1               0             0 2 1 ?
*> 172.23.0.0       0.0.0.0                  0         32768 ?
*> 10.21.1.1/32     172.22.1.1                             0 2 1 2 i
*>i10.52.1.0/24     192.168.3.1              0    100      0 ?
*>i10.52.2.1/32     192.168.3.1              0    100      0 3 i
*>i10.52.3.1/32     192.168.3.1              0    100      0 3 i
*> 10.99.1.1/32     0.0.0.0                  0         32768 ?
*> 10.99.2.2/32     172.22.1.1               0             0 2 1 ?

                  The output of the show ip bgp vpnv4 vrf command for a specified VRF displays the router ID in the output header: 

                  Router# show ip bgp vpnv4 vrf vrf_user

BGP table version is 43, local router ID is 10.99.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
   Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 65500:1 (default for vrf vrf_user) VRF Router ID 10.99.1.1
r> 172.22.0.0       172.22.1.1               0             0 2 1 ?
*> 172.23.0.0       0.0.0.0                  0         32768 ?
*> 10.21.1.1/32     172.22.1.1                             0 2 1 2 i
*>i10.52.1.0/24     192.168.3.1              0    100      0 ?
*>i10.52.2.1/32     192.168.3.1              0    100      0 3 i
*>i10.52.3.1/32     192.168.3.1              0    100      0 3 i
*> 10.99.1.1/32     0.0.0.0                  0         32768 ?
*> 10.99.2.2/32     172.22.1.1               0             0 2 1 ?

                  The output of the show ip bgp vpnv4 vrf summary command for a specified VRF displays the router ID in the first line of the output: 

                  Router# show ip bgp vpnv4 vrf vrf_user summary

BGP router identifier 10.99.1.1, local AS number 45000
BGP table version is 43, main routing table version 43
8 network entries using 1128 bytes of memory
8 path entries using 544 bytes of memory
16/10 BGP path/bestpath attribute entries using 1856 bytes of memory
6 BGP AS-PATH entries using 144 bytes of memory
3 BGP extended community entries using 72 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 3744 total bytes of memory
BGP activity 17/0 prefixes, 17/0 paths, scan interval 15 secs
Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
172.22.1.1      4     2      20      21       43    0    0 00:12:33        3

                  When the path is sourced in the VRF, the correct router ID is displayed in the output of the show ip bgp vpnv4 vrfcommand for a specified VRF and network address: 

                  Router# show ip bgp vpnv4 vrf vrf_user 172.23.0.0

BGP routing table entry for 65500:1:172.23.0.0/8, version 22
Paths: (1 available, best #1, table vrf_user)
  Advertised to update-groups:
     2          3         
  Local
    0.0.0.0 from 0.0.0.0 (10.99.1.1)
      Origin incomplete, metric 0, localpref 100, weight 32768, valid, sourced, best
      Extended Community: RT:65500:1

                  Example: Automatically Assigning a BGP Router ID per VRF

                  The following three examples show different methods of configuring BGP to automatically assign a separate router ID to each VRF instance.

                  Globally Automatically Assigned Router ID Using Loopback Interface IP Addresses

                  The following example shows how to configure two VRFs—vrf_trans and vrf_user—with sessions between each other on the same router. Under router configuration mode, BGP is globally configured to automatically assign each VRF a BGP router ID. Loopback interfaces are associated with individual VRFs to source an IP address for the router ID. The show ip bgp vpnv4 command can be used to verify that the router IDs have been configured for each VRF. 

                  ip vrf vrf_trans
 rd 45000:1
 route-target export 50000:50
 route-target import 40000:1
!
ip vrf vrf_user
 rd 65500:1
 route-target export 65500:1
 route-target import 65500:1
!
interface Loopback0
 ip address 10.1.1.1 255.255.255.255
!
interface Loopback1
 ip vrf forwarding vrf_user
 ip address 10.99.1.1 255.255.255.255
!
interface Loopback2
 ip vrf forwarding vrf_trans
 ip address 10.99.2.2 255.255.255.255
!
interface Ethernet0/0
 ip vrf forwarding vrf_trans
 ip address 172.22.1.1 255.0.0.0
!
interface Ethernet1/0
 ip vrf forwarding vrf_user
 ip address 172.23.1.1 255.0.0.0
!
router bgp 45000
 bgp router-id vrf auto-assign
 no bgp default ipv4-unicast
 bgp log-neighbor-changes
 neighbor 192.168.3.1 remote-as 45000
 neighbor 192.168.3.1 update-source Loopback0
 !
address-family vpnv4
  neighbor 192.168.3.1 activate
  neighbor 192.168.3.1 send-community extended
  exit-address-family
 !
 address-family ipv4 vrf vrf_user
  redistribute connected
  neighbor 172.22.1.1 remote-as 40000
  neighbor 172.22.1.1 local-as 50000 no-prepend
  neighbor 172.22.1.1 ebgp-multihop 2
  neighbor 172.22.1.1 activate
  neighbor 172.22.1.1 allowas-in 1
  no auto-summary
  no synchronization
  exit-address-family
 !
 address-family ipv4 vrf vrf_trans
  redistribute connected
  neighbor 172.23.1.1 remote-as 50000
  neighbor 172.23.1.1 local-as 2 no-prepend
  neighbor 172.23.1.1 ebgp-multihop 2
  neighbor 172.23.1.1 activate
  neighbor 172.23.1.1 allowas-in 1
  no auto-summary
  no synchronization
  exit-address-family

                  After the configuration, the output of the show ip bgp vpnv4 all command shows the router ID displayed next to the VRF name. Note that the router IDs used in this example are sourced from the IP addresses configured for loopback interface 1 and loopback interface 2. The router IDs are the same as in the “Example: Manually Configurinig a BGP Router ID per VRF” section. 

                  Router# show ip bgp vpnv4 all

BGP table version is 43, local router ID is 10.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
   Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 45000:1 (default for vrf vrf_trans) VRF Router ID 10.99.2.2
*> 172.22.0.0       0.0.0.0                  0         32768 ?
r> 172.23.0.0       172.23.1.1               0             0 3 1 ?
*>i10.21.1.1/32     192.168.3.1              0    100      0 2 i
*> 10.52.1.0/24     172.23.1.1                             0 3 1 ?
*> 10.52.2.1/32     172.23.1.1                             0 3 1 3 i
*> 10.52.3.1/32     172.23.1.1                             0 3 1 3 i
*> 10.99.1.1/32     172.23.1.1               0             0 3 1 ?
*> 10.99.1.2/32     0.0.0.0                  0         32768 ?
Route Distinguisher: 50000:1
*>i10.21.1.1/32     192.168.3.1              0    100      0 2 i
Route Distinguisher: 65500:1 (default for vrf vrf_user) VRF Router ID 10.99.1.1
r> 172.22.0.0       172.22.1.1               0             0 2 1 ?
*> 172.23.0.0       0.0.0.0                  0         32768 ?
*> 10.21.1.1/32     172.22.1.1                             0 2 1 2 i
*>i10.52.1.0/24     192.168.3.1              0    100      0 ?
*>i10.52.2.1/32     192.168.3.1              0    100      0 3 i
*>i10.52.3.1/32     192.168.3.1              0    100      0 3 i
*> 10.99.1.1/32     0.0.0.0                  0         32768 ?
*> 10.99.1.2/32     172.22.1.1               0             0 2 1 ?

                  Globally Automatically Assigned Router ID with No Default Router ID

                  The following example shows how to configure a router and associate a VRF that is automatically assigned a BGP router ID when no default router ID is allocated. 

                  ip vrf vpn1
 rd 45000:1
 route-target export 45000:1
 route-target import 45000:1
!
interface Loopback0
 ip vrf forwarding vpn1
 ip address 10.1.1.1 255.255.255.255
!
interface Ethernet0/0
 ip vrf forwarding vpn1
 ip address 172.22.1.1 255.0.0.0
!
router bgp 45000
 bgp router-id vrf auto-assign
 no bgp default ipv4-unicast
 bgp log-neighbor-changes
 !
 address-family ipv4 vrf vpn1
  neighbor 172.22.1.2 remote-as 40000
  neighbor 172.22.1.2 activate
  no auto-summary
  no synchronization
  exit-address-family

                  Assuming that a second router is configured to establish a session between the two routers, the output of the show ip interface brief command shows only the VRF interfaces that are configured. 

                  Router# show ip interface brief

Interface              IP-Address      OK? Method Status                Protocol
Ethernet0/0            172.22.1.1      YES NVRAM  up                    up      
Ethernet1/0            unassigned      YES NVRAM  administratively down down    
Serial2/0              unassigned      YES NVRAM  administratively down down    
Serial3/0              unassigned      YES NVRAM  administratively down down    
Loopback0              10.1.1.1        YES NVRAM  up                    up

                  The show ip vrf command can be used to verify that a router ID is assigned for the VRF: 

                  Router# show ip vrf

Name                             Default RD          Interfaces
  vpn1                             45000:1             Loopback0
                                                       Ethernet0/0
VRF session is established:

                  Per-VRF Automatically Assigned Router ID

                  The following example shows how to configure two VRFs—vrf_trans and vrf_user—with sessions between each other on the same router. Under the IPv4 address family associated with an individual VRF, BGP is configured to automatically assign a BGP router ID. Loopback interfaces are associated with individual VRFs to source an IP address for the router ID. The output of the show ip bgp vpnv4 command can be used to verify that the router IDs have been configured for each VRF. 

                  ip vrf vrf_trans
 rd 45000:1
 route-target export 50000:50
 route-target import 40000:1
!
ip vrf vrf_user
 rd 65500:1
 route-target export 65500:1
 route-target import 65500:1
!
interface Loopback0
 ip address 10.1.1.1 255.255.255.255
!
interface Loopback1
 ip vrf forwarding vrf_user
 ip address 10.99.1.1 255.255.255.255
!
interface Loopback2
 ip vrf forwarding vrf_trans
 ip address 10.99.2.2 255.255.255.255
!
interface Ethernet0/0
 ip vrf forwarding vrf_trans
 ip address 172.22.1.1 255.0.0.0
!
interface Ethernet1/0
 ip vrf forwarding vrf_user
 ip address 172.23.1.1 255.0.0.0
!
router bgp 45000
 no bgp default ipv4-unicast
 bgp log-neighbor-changes
 neighbor 192.168.3.1 remote-as 45000
 neighbor 192.168.3.1 update-source Loopback0
 !
address-family vpnv4
  neighbor 192.168.3.1 activate
  neighbor 192.168.3.1 send-community extended
  exit-address-family
!
 address-family ipv4 vrf vrf_user
  redistribute connected
  neighbor 172.22.1.1 remote-as 40000
  neighbor 172.22.1.1 local-as 50000 no-prepend
  neighbor 172.22.1.1 ebgp-multihop 2
  neighbor 172.22.1.1 activate
  neighbor 172.22.1.1 allowas-in 1
  no auto-summary
  no synchronization
  bgp router-id auto-assign
  exit-address-family
 !
 address-family ipv4 vrf vrf_trans
  redistribute connected
  neighbor 172.23.1.1 remote-as 50000
  neighbor 172.23.1.1 local-as 40000 no-prepend
  neighbor 172.23.1.1 ebgp-multihop 2
  neighbor 172.23.1.1 activate
  neighbor 172.23.1.1 allowas-in 1
  no auto-summary
  no synchronization
  bgp router-id auto-assign
  exit-address-family

                  After the configuration, the output of the show ip bgp vpnv4 all command shows the router ID displayed next to the VRF name. Note that the router IDs used in this example are sourced from the IP addresses configured for loopback interface 1 and loopback interface 2. 

                  Router# show ip bgp vpnv4 all

BGP table version is 43, local router ID is 10.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
   Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 45000:1 (default for vrf vrf_trans) VRF Router ID 10.99.2.2
*> 172.22.0.0       0.0.0.0                  0         32768 ?
r> 172.23.0.0       172.23.1.1               0             0 3 1 ?
*>i10.21.1.1/32     192.168.3.1              0    100      0 2 i
*> 10.52.1.0/24     172.23.1.1                             0 3 1 ?
*> 10.52.2.1/32     172.23.1.1                             0 3 1 3 i
*> 10.52.3.1/32     172.23.1.1                             0 3 1 3 i
*> 10.99.1.1/32     172.23.1.1               0             0 3 1 ?
*> 10.99.1.2/32     0.0.0.0                  0         32768 ?
Route Distinguisher: 50000:1
*>i10.21.1.1/32     192.168.3.1              0    100      0 2 i
Route Distinguisher: 65500:1 (default for vrf vrf_user) VRF Router ID 10.99.1.1
r> 172.22.0.0       172.22.1.1               0             0 2 1 ?
*> 172.23.0.0       0.0.0.0                  0         32768 ?
*> 10.21.1.1/32     172.22.1.1                             0 2 1 2 i
*>i10.52.1.0/24     192.168.3.1              0    100      0 ?
*>i10.52.2.1/32     192.168.3.1              0    100      0 3 i
*>i10.52.3.1/32     192.168.3.1              0    100      0 3 i
*> 10.99.1.1/32     0.0.0.0                  0         32768 ?
*> 10.99.1.2/32     172.22.1.1               0             0 2 1 ?

                  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

                  MPLS commands

                  Cisco IOS Multiprotocol Label Switching Command Reference

                  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

                  —

                  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

                  No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature.

                  —

                  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 Per-VRF Assignment of BGP Router ID

                  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 . An account on Cisco.com is not required.
                  Table 1 Feature Information for Per-VRF Assignment of BGP Router ID

                  Feature Name

                  Releases

                  Feature Information

                  Per-VRF Assignment of BGP Router ID

                  12.2(31)SB2

                  12.2(33)SRA

                  12.2(33)SXH

                  12.4(20)T

                  15.0(1)S

                  The Per-VRF Assignment of BGP Router ID feature introduces the ability to have VRF-to-VRF peering in Border Gateway Protocol (BGP) on the same router. BGP is designed to refuse a session with itself because of the router ID check. The per-VRF assignment feature allows a separate router ID per VRF using a new keyword in the existing bgp router-id command. The router ID can be manually configured for each VRF or can be assigned automatically either globally under address family configuration mode or for each VRF.

                  The following commands were introduced or modified by this feature: bgp router-id, show ip bgp vpnv4.