Automatic Tunnels

The preferred method for creating automatic tunnels is through 6to4 tunneling. For detailed information about the 6to4 routing and tunneling mechanism, refer to 6to4 as a Transition Mechanism.

Automatic tunnels require IPv4–compatible addresses. Automatic tunnels can be used to connect IPv6 nodes when IPv6 routers are not available. These tunnels can originate either on a dual host or on a dual router by configuring an automatic tunneling network interface. The tunnels always terminate on the dual host. These tunnels work by dynamically determining the destination IPv4 address, the endpoint of the tunnel, by extracting the address from the IPv4–compatible destination address.