It wouldn't necessarily have to be NAT. Any firewall without an explicit policy rule allowing the traffic.
Hi Jim! I'm in the same boat as the others - or similar -
I don't run a software firewall at the moment on the Windows box which serves as IPv6 router and local tunnel endpoint. If it were a firewall thing, it would have to be inside the Speedtouch ST510 box, but that ain't it because 1) I have explicit firewalling disabled in the ST router, 2) if it were an (implicit?) rule blocking traffic somewhere along the chain, things would not work AT ALL. That it works correctly for minutes proves it is not this kind of settings problem.
What I experience and, I think, Jgadmin, Donald and others also have been experiencing is traffic inside the tunnel ceasing after X minutes, while the tunnel itself remains formally open.
A first thought would be dynamical NAT entries timing out, but the tunnel dies out even while pinging the end point constantly at 1 second intervals.
I even tried this : in the router, unbind the "helper" applications for proto 47 (GRE) and PPTP (TCP :1723) and establish FIXED mappings to the windows box instead [like I do, with success, for proto 41]. Unfortunately, in this instance it doesn't work ! Either I goofed while unbinding/reNATting, or the problem may be on HE's side.
I'd appreciate feedback/ help / diagnosing ideas from both the HE people on the one hand, you and the other Masters OTOH. Did I forget about some server addresses/ ports/ protos ?
JimB, you are telling you have got NO problem ? Are you connected directly to a public IP or behing a local NAT ? I could try a direct connection - by temporarily replacing the ST 510 by my old ST 330 (ADSL on USB) but I am not in a hurry to do that if it could be avoided at all...