Special issues with 6to4 mainly relate to the way IPv6-in-IPv4 tunnels are set up automatically and the security issues arising when somebody operates a (public) 6to4 relay. For the following section a 6to4 host or router is a host with just a 6to4 pseudo interface. This host might or might not have native IPv6 connectivity. Similarly it might or might not announce its 6to4 prefix to a subnet and thereby act as IPv6 access/default router for this subnet. A 6to4 relay is a dual-stack host with a 6to4 pseudo interface, which forwards packets between the 6to4 domain (2002::/16) and the rest of the IPv6 Internet. A 6to4 relay is also a 6to4 host.

In terms of management and security a network for which a 6to4 host acts as a border router is not affected by the fact that the border router uses 6to4 to provide outside connectivity (either globally or just within the 6to4 domain) aside from the fact that this network’s IPv6 connectivity of course depends on the 6to4 connectivity of the 6to4 host.