Re: Some ISP's will (Score 1)

We apply anti-spoofing access lists on all our customer edge routers, on both inbound interfaces (to stop their naughty people, and protect them from other ISP's naughty people where the ISP hasn't done this). Most of the edge routers aren't that busy, and the list is usually pretty short. We don't do anything like this on our core routers or border routers with our upstreams due to the overhead.