[c-nsp] BGP Question

[Justin M. Streiner]

On Wed, 8 Jun 2005, Mark Tohill wrote:

> If we peer with an upstream provider 'piggybacking' on their AS due to
> legacy issues, can we announce a new portion of address space via the
> network statement on our iBGP peers. Will this get announced the the
> Net, or does also need done at eBGP peers i.e our upstreams edge
> routers?

Assuming you get the new IP space from that upstream provider, or 
possibly provider-independent space from your local RIR (ARIN, RIPE, 
APNIC, etc), it should be OK.  Different providers will have different 
policies, but typically semi-private ASNs like AS7046 for UUNET are only 
to be used by customers who only have connectivity with that AS.

> I suppose what I'm asking here is does information from iBGP routers get
> propogated to eBGP routers and onward.

If you're doing a semi-private AS arrangement with your upstream, they 
will probably be speaking EBGP since the AS you're in will likely be 
different than the provider's backbone AS.

jms