There are services like Prolexic and Defense.net that you advertise your routes to, then they send you clean traffic. Providers won't care if you asked for the

There are services like Prolexic and Defense.net that you advertise your routes to, then they send you clean traffic. Providers won't care if you asked for the traffic or not. You'll get billed. They won't put in an ACL. Not today. 5 years ago, maybe. Today, no chance. They'll want to sell you their own DDoS mitigation services (at hefty fees). TWTC (and others) will sell you a "clean pipe" option which includes mitigation, and you only pay for what passes through mitigation. It's more expensive than regular transit, but it's an option if you want to keep things simple. ACLs are not an option today.