Routing

Hi All,

I am trying to set up a bgp community so that if a bgp transit customer uses it, it will automatically prepend the AS x amount of times.  Now....is it best to prepend my AS ( which i have managed to write a policy for ) or is there a way with a regexp to add his AS to the prepend?

Any thoughts/suggestions much appreciated.

Nick

Hello,

There's a very flexible way, using predefined(customer independent) communities and as-path-expand statement.

The point is that the AS number of your peer (from which the prefix you have received) will be prepended, not the AS number of the originating AS. 

community prepend-1 65000:1; 

community prepend-2 65000:2;

policy-statement prepend { 
term prepend-1 { 
from community prepend-1; 
then as-path-expand last-as; 
} 
term prepend-2 { 
from community prepend-2; 
then as-path-expand last-as count 2; 
} 

Hi Dumitru,

Thats exactly what I'm looking for.  Thanks so much!