[j-nsp] How to prefer short prefixes ?

[Paul Goyette]

> We have a public peer who is announcing certain routes
> which of length /19 or shorter.  However we are also
> learning more specific routes (21-24) for the same
> entity via our upstream (transit provider). Needless
> to say the traffic bound for that entity uses our
> upstream. 
> 
> Is there is a way that where I can make the routes
> leaned via our public peer more attractive ? Tweaking
> local pref does not work in this case because the
> forwarding table always prefer more specific routes. 

Two solutions:

1. Have your public peer advertise the shorter
   prefixes to you - so you can prefer them over
   the upstream.

2. Filter the shorter prefix announcements from
   the upstream.

Presumably, your public peer owns the entire /19,
so why are they advertising the whole thing to 
you but only bits and pieces to someone else?

Paul Goyette
Juniper Networks Customer Service