Need your input for my scenario, we have 8 sites (Site 1 - 6, Site A & Site B) which connected to AT&T cloud with BGP running, we manage our CE router. Site A & Site B also have Internet connection from local providers, and these 2 sites (Site A & Site B) are generating a route zero through AT&T BGP network for Site 1 - 6 as an Internet Gateway. Currently Site 1 - 6 are pointing Site A as the Internet Gateway.
My question is there any method so that I can control Site 1 - 3 can access Internet through Site A and Site 4 -6 can access Internet through Site B without involve AT&T PE routers?
Appreciate for any idea?