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  • 1.  Why do I need a gateway IP configured on an interface, which peers with a BGP neighbor?

     
    Posted 03-21-2018 00:00


  • 2.  RE: Why do I need a gateway IP configured on an interface, which peers with a BGP neighbor?

    Posted 03-21-2018 00:00

    It is mainly for ARP. The BGP neighbor will not be in an off subnet IP. So when we ARP for it, we need an on subnet IP which will be the default gateway on the interface.



  • 3.  RE: Why do I need a gateway IP configured on an interface, which peers with a BGP neighbor?

     
    Posted 03-21-2018 00:00

    Ritesh Mukherjee Thanks for your response. So, if I understand your answer, if the BGP peer has an off-subnet IP, then we do need an on-subnet IP, i.e the gateway, for ARP purposes. I get that. But is it possible that a BGP peer has an on-subnet IP instead, in which case, I guess, we wouldn't need a gateway IP?



  • 4.  RE: Why do I need a gateway IP configured on an interface, which peers with a BGP neighbor?

    Posted 03-21-2018 00:00

    If you have a recursive route to resolve the neighbor, I would think this would not be needed as routing should push down the interface as gateway. However this behavior needs to be tested/confirmed.



  • 5.  RE: Why do I need a gateway IP configured on an interface, which peers with a BGP neighbor?

    Posted 03-21-2018 00:00

    Hello, BGP assumes neighbors are adjacent unless the mulithop parameter is configured. Adjacent endpoints shouldn't need a gateway.