We have an ASA that has been doing iBGP for hosted networks. These networks include public address spaces that are routed inside our networks.
Recently we have changed providers. The new provider does not do static routing (which previously forwarded our networks to us), and requires BGP.
So, we have an existing private AS on the 5500 and all the devices behind it have private AS numbers. It all works beautifully.
I started looking into hosting multiple AS on the 5500 and found nothing really. I have configured the BGP neighbor with remote and local AS so that we can spoof the new AS number assigned by the new provider.
The issue now, is I can't find a way to manually advertise our public class C to this one specific neighbor. I do not want it in my routing tables due to its impact on the internal routes. I simply need to advertise to the provider to send anything in this subnet to me.
So, does anyone know the trick to configure BGP to only advertise x.x.x.x/24 with next hop y.y.y.y on AS zzzz to neighbor a.a.a.a?