You might want to try pinging the link-local address to narrow it down between a firewall or other networking problem between the two hosts, and a Teredo problem. I have heard of problems where, when using Teredo-based IPv6 addresses, you cannot ping other machines on your own subnet. For example, I can ping a Windows 7 machine on the same network as my Ubuntu machine by doing this (on my Ubuntu machine):
$ ping6 -c 5 -I eth0 fe80::e1ce:694a:18c0:6530
Note, the -I
argument is important when pinging a link-local address because otherwise the host OS has no way to know which link-local interface you're talking about. (for all it knows, you want to use the Teredo interface, or the loopback interface, for example.)
Please provide examples of how you are pinging the machine. – Jeremy Visser – 2011-02-21T11:57:04.017