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Forum Replies

  1. Hi Rene,

    I want to know the configuration, where the customer will be using bgp protocol.

    what will be the steps for CE1 to PE1, PE1-P-PE2, CE2to PE2.

    kindly reply.

    S Alladi

  2. HI Rene,

    you mentioned two methods to solve the two same AS issue.

    Use Allow-AS in to overrule the loop prevention mechanism of external BGP.
    Use AS override to change the AS number on the PE routers.

    my question is that among both method which method should I use for which situation?

    Nyi Nyi.

  3. Hi Nyi Nyi,

    Both will get the job done, the main difference is that allow AS in is configured on the customer routers and AS override is done on the SP routers. In the real world you probably don’t have access to both the customer and SP routers so it’s possible that only one of the two options is available to you.


  4. Hi Rene,
    everything was clear about this lesson but am confused why did you configure AS 12 on Router CE1? It should have been AS1. If we configure different AS then we dont have to use Allowas-in command, right?

    hostname CE1
    interface Loopback0
     ip address
    interface GigabitEthernet0/1
     ip address
     duplex auto
     speed auto
     media-type rj45
    router bgp 12
     bgp log-neighbor-changes
     network mask
     neighbor remote-as 234
     neighbor allowas-in

  5. Hi Eleever,

    You mean this part?

     address-family ipv4
      no neighbor activate
     address-family vpnv4
      neighbor activate
      neighbor send-community extended

    What is does is that we don’t exchange IPv4 unicast routes but only VPNv4 routes with our neighbor.


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