FAQ : Connectivity (Tunnels and Subnets) : I have a firewall, what ports/protocols are used?
I have a firewall, what ports/protocols are used?
Paranoid and want to seal everything off? Or are you behind a NAT and want to know what to expect? The following ports/protocols may be used by SixXS tunnels and their configuration tools.
Note that we do not provide IPv6 connectivity to locations where the IPv6 tunnel would circumvent a local policy formed by for instance a firewall. Most corporate networks forbid forms of tunneling as this would open a channel over which an attack into their corporate network could take place as it bypasses the policies implemented in their firewalls. If you are in such a situation, don't try to circumvent your administrators policy but talk to them and try and get IPv6 connectivity setup together with them according to their policies, it is their network afterall, not yours.
Network administrators can easily block the usage of SixXS by blocking the above ports.