If filter policies like Sprint's and Verio's really are common among the big backbone providers, that would seem to make it relatively pointless to attempt to multi-home with provider supplied IP space. We have a customer interested in multihoming for reliability, but they use so little IP space, even assigning them a /24 would be a stretch. Since the space we let them use is in 209.x.x.x, it seems their route wouldn't get far. So how do they make their internet connection more reliable? Use IP space from each of their providers and play games with DNS and NAT?
Yes, or get their provider to give them a chunk of swamp space (which a few have tucked away), multihome with the same provider, or find a way to justify a routable allocation. None of these are, IMO, very good solutions. Austin