[c-nsp] BGP - Multihop across igp network

[Jon Lewis]

On Tue, 6 Apr 2010, Paul Stewart wrote:

> I've run into a scenario and confused - this list is so helpful .. at the
> risk of sounding like a dummy here I'm posting anyways LOL
>
> We have two core BGP boxes (7600's).  Everything is fine with them.
>
> Connected to these 7600's we have a pair of 6500's not doing BGP (however
> participating in OSPF as all our boxes do)
>
> Connected off one of the 6500's we have a 3825 at a customer site
>
> The customer who is connected to a 3825 wants a full BGP feed from us.

When the customer connected to the 3825 advertises routes to you, how do 
the 6500s know about those routes?  If they don't, when traffic hits them 
destined for those addresses, they may forward it back the wrong direction 
instead of down through the 3825.

What you might want to do is have the 6500s do iBGP, but assuming you 
don't want them to have (or they can't handle) full routes, only feed them 
internal/customer routes.

----------------------------------------------------------------------
  Jon Lewis                   |  I route
  Senior Network Engineer     |  therefore you are
  Atlantic Net                |
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