[c-nsp] Dual-homing scenario

[Vincent De Keyzer]

Hello,

 

let a dual-home BGP network. ISP1 comes in with a T3 and sends a full BGP
table; ISP2 comes with a FE and a default-route (for memory reasons).

 

ISP2 is preferrable because of capacity, but ISP1 is preferred because any
route is more specific than a default route; hence all upstream traffic goes
to ISP1, which is not good.

 

Still, it would be nice to keep sending *some* traffic to ISP1; but most of
the traffic should go to ISP2.

 

One way I see to achieve this would be to local-pref based on AS path: if
the route comes from ISP1's AS, or from an AS directly connected to ISP1,
local-pref it with 130; else local-pref it with 100 (and local-pref the
default route from ISP2 with 120).

 

Is this a good way to do it? 

 

Take into account that ISP1 is not very flexible (and ISP2 is flexible, but
likes simple things). :-)

 

Vincent