[c-nsp] Peering + transit backup between 2 ISPs

[Vincent De Keyzer]

Hello,

 

let ISP A and ISP B, which both have routers in a given room. They are good
friends and they would like to achieve the following:

1.	set-up a peering to exchange own AS routes
2.	serve as backup transit one for the other: each ISP would have one
upstream only, and when the unique upstream goes down, it would then (and
only then) use the other ISP for transit 

 

Is this feasible? I can't really figure out how this could be achieved
without having both ISPs offering transit to each other all of the time.

 

Vincent