EBGP over unnumbered serial lines

[Radha Gowda <[e-mail]>]

Here is Yakov's response to my question on whether it makes sense to
support external BGP over unnumbered serial lines.  Yakov suggested
that we bring this issue up in the mailing list.  All comments are 
welcome.

> I think that the "same subnet" restriction is mostly intended to
> make sure that the external neighbors are one hop away from each 
> other (on a common Data Link subnetwork). I think the key question
> you need to answer is what you are going to put in the NEXT_HOP attribute,
> and whether what you'll put in the NEXT_HOP attribute would cause
> any problems to the neighbor (when the neighbor receive a route with
> this attribute).  I suspect (but I am not sure), that there
> may be some problems associated with what you put in the NEXT_HOP
> when you have serial line with unnumbered interfaces.