Unfortunately, the actual core area of a router lack of features.
SixXS tunnels are supported for IPv6, but not the important AYIYA protocol. If you can use the router as Exposed Host refusing resistant build IPv6 tunnel, because he thinks he would not depend on the Internet.
If one connects two Fritz boxes with VPN can no longer call you as soon as the VPN pipe is full. Unfortunately, there is then no options specific ports for the VPN to terminate. One of the core tasks of a router normally is certain ports and IP addresses to forward / or different. Unfortunately, to block, it did not work or only very rudimentary.
