[nsp] Routing Problem: I am not sure where to begin.

[Jim Devane]

Justin,

Thank you for your reply. 

I can see where the loopback peering would work downstream to the 7206,
Mapping the /32 address to each to each of the ports and to the next hop.
Makes sense.

But I am not sure what address the 7206 would peer with. It seems like it
would require 2 sessions. (one for each router, since they are separate L3
devices)

How would I have the same loopback on both routers? If I did not have the
same IP on both routers, then I would have 2 sessions, no? And if I do use 2
ip's (each loopback on each GSR, how can I have one session stay down but
automatically come up on the protect link) 

I know that putting bgp in an admin down sense would work, but not very
dynamic.

Am I being a complete idiot?

Thanks again,
Jim


-----Original Message-----
From: Ryburn, Justin [mailto:justin.ryburn at xo.com] 
Sent: Monday, December 15, 2003 1:11 PM
To: Jim Devane; Jack.W.Parks at alltel.com; cisco-nsp at puck.nether.net
Subject: RE: [nsp] Routing Problem: I am not sure where to begin.

>I don't want to tie the BGP session to just one router and I don't want
more
>than 1 BGP session.
>
>Meaning, if I run BGP to the interface IP then BGP *should* never go
down
>when the interface changes.

Sounds like a perfect scenario for loopback peering.  You can statically
route a /32 to both interfaces (assuming different IPs like Jack
suggested) in both routers and then do an ebgp-multihop BGP session
between them.

Hope that helps.

Justin