First, IPv6 functionality should be enabled on the Windows XP host as described in Appendix B. If there is no native IPv6 on the LAN the host is connected to, the operating system configures a “6to4 Tunnelling Pseudo-Interface” and adds a default route pointing to Microsoft’s Research 6to4 relay router, i.e. 6to4.ipv6.microsoft.com. This allows you to initially test the newly enabled IPv6 stack and its functionality through the “tracert6” command while pointing to the above host. Unfortunately, this automatically enabled configuration will not allow you to establish a connection to any other IPv6 host or networks.

In order to establish connectivity with other IPv6 networks, such as 6NET, the 6to4 tunnel should be configured to point to a free 6to4 relay router. For example, the following command

C:/>netsh interface ipv6 6to4 set relay x.y.w.z

points the host’s 6to4 tunnel to the 6to4 relay router with the IPv4 address x.y.w.z.

In order for this 6to4 client to serve a whole subnet as IPv6 default router, the /48-prefix, the host configured itself with needs to be advertised on the normal LAN interface. Also the default route needs to be specifically set to be published:

C:/>netsh interface ipv6 add route 2002:<IPv4 address in hex>::/48 \\
<number of normal LAN interface> publish=yes \\
validlifetime=<valid lifetime of route> \\
preferredlifetime=<period for which the route is preferred>
C:/>netsh interface ipv6 set route ::/0 \\
<name or number of 6to4 interface> publish=yes