Comment Why would Verizon "block" this IPv6 space? (Score 2, Interesting) 438
From the article it's not clear if Verizon is actively blackholing those prefixes, filtering them from their peers, or if they lack transit to the ASes from which the prefixes come.
I find it hard to believe that even Verizon is so disorganized that they would blackhole or filter that large a chunk of IPv6-land. My guess is that the situation is that not all of the Tier 1s have their IPv6 peering agreements in place yet. As we've learned from the various "depeering" events over the years, if a Tier 1 isn't hearing another Tier 1's route from that AS, they're not going to get it from their other peers, because that would cause the other peers to act like transit providers, and Tier 1s really don't like providing transit for eachother.
In other words, traffic for those prefixes probably doesn't leave 701 because 701 doesn't know where to send it.
The way the Internet is built it's not possible for any network to guarantee transit between you and a specific AS or prefix. There are so many factors external to a provider's network that could cause them to not know the route, or other issues that I don't even want to try to list 'em all. Simple little things like the owner of the prefix deciding not to advertise it to your network can look like this. This is also why the FCC or other government agencies don't have a hope of regulating peering agreements.
I can't believe I'm coming to Verizon's defense here...