I have two Linux Debian machines in my house. They were both working fine with HE IPv6 tunnel. I backed up /etc/network/interfaces on one of them and I reinstalled the OS. I am sure the settings in /etc/network/interfaces are correct but I do not have IPv6 access. I can only think that there is some other setting in the OS? please give me your thoughts as what the problem could be.
Can you post what you're trying to use? More details are helpful