I have two standard HE tunnels, one for my home network in New York (handled by a FreeBSD 7 system) and one for a Slicehost VM in Dallas (running Ubuntu 8.04). It seems that my tunnels cease to allow inbound traffic after a period of inactivity, and I wanted to check and see if this is normal behavior.
For example, right now from home I can ping6 ipv6.google.com no problem, replies coming back nice and quick. However, if I ping6 the endpoint of my tunnel in Dallas, I don't get a reply. If I try to telnet -6 to any of the listening ports there, no connection opens. However, if I ssh into that Dallas system via IPv4 and ping ipv6.google.com, I get replies. And immediately thereafter, everything that would time out just a moment before (pings, connections) start working. But if I let things idle for a while (I'm not yet sure how long it takes), the problem comes back.
I'd been hoping to set up my Slicehost VM to be able to provide services (HTTP, SMTP, etc.) over IPv6 in addition to IPv4, but it seems like this timeout issue makes it difficult to do that reliably. Is this normal, or am I doing something wrong?