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Forum Replies

  1. Hi Hamood,

    That’s right, if you source eBGP from the loopback interfaces then you’ll need multihop.

    The problem with the R1-R2-R3 scenario is that R2 will never learn about any prefixes, when R1 tries to reach a network behind R3 (or R3 wants to reach something behind R1) then R2 will receive an IP packet with a destination it doesn’t know about.

    If you really had to use eBGP between R1 and R3 then a GRE tunnel might be a solution…


  2. Hi Rene,

    Why you enable the directly connected check again when you increase the TTL ?


  3. Hi Jason,

    R1(config-router)# neighbor remote-as 2

    That command instructs R1 to establish a neighbor relationship with It does not, however, tell R1 to use any specific interface as source or “from” address when establishing the relationship. By default, BGP will try to use the closest interface to the neighbor to establish the relationship. Knowing this, what do you suppose would happen if we just used the command above to try to establish a BGP neighbor relationship with R2?

    From R2’s perspective it would be receiving packets from R1, but t

    ... Continue reading in our forum

  4. Sara,
    I am not quite following what you are asking. Are you asking why you would have a neighbor statement, but not a corresponding network statement? If so, the most common example of this would be a company that wants to form a neighbor relationship with its ISP’s BGP router in order to get routes in–usually just a default route (if there is only one exist point), or sometimes all routes within the ISP’s autonomous system. In either case, there might be no need for the customer to advertise anything out to the ISP.

    If I have misunderstood your question, please clarify.


  5. I’m still not clear on why the second scenario requires multihop when the neighbours are directly connected.

    Are you saying that when traffic is sourced from and to a loopback, it is effectively taking 3 hops? (2 of which are virtual within the routers).

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