Unix (linux) tracroute -P . It only stops there if the proto is 41. 47, 4, 19, 88, whatever, all go through just fine. (PM me if you want to do some traces yourself)
My tests are run between my DSL and IPDSL endpoints from an Earthlink MetroE line, and my TWC line (the 2fff::/64 nonsense tunnel -- ::1 being TWC, ::2 being IPDSL, since I cannot see what's going on at HE.net.) And, BTW, it does the same thing to a local VDSL Uverse line. (and that one has a 2wire RG)
[Note: I'm using static blocks from the RG in both cases.]