Is the export policy selective under valley-free?

Paul Wall pauldotwall at
Tue Sep 2 19:23:43 CDT 2008


That's correct.  A network purchasing transit will advertise its
internally-originated prefixes, as well as those it's learning from
downstream customers, to its provider.

(At least that's the theory.  It's not terribly uncommon for transit
purchasers to advertise a full table, or for their providers to have
lax or non-existent filters, but that's neither here nor there. :)

I'm not sure what "valley-free" means in this context.  You might want
to try the Rosetta Stone patches and make sure your copy is up to

Drive Slow,
Paul Wall

On Tue, Sep 2, 2008 at 7:45 PM, Kai Chen <kch670 at> wrote:
> Just want to ask a direct question. Will an AS export all it gets from
> its customers and itself to its providers? Or even under valley-free,
> the BGP export policy is also selective?
> Thanks a lot,
> --
> -Kai

More information about the NANOG mailing list