Hi there,
Also do add the following for the Linux based tunnel configurations, as I've just had an issue with a company where they block ICMP6 on their firewalls/webservers, so I couldn't access the sites from behind a Linux based tunnel:
ip6tables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu