IPv6 – Manual Tunneling
A manually configured tunnel is a permanent virtual link between two IPv6 networks connecting over an IPv4 backbone. Manual configured tunnels can carry IPv6 packets only. A v6 address is configured on the tunnel interface, along with this a manual v4 addresses are configured on the source and the destination of the tunnel, configured tunnels must have both v4 and v6 addresses.
Routers at the source and destination of the tunnel must have IPv4 and IPv6 dual stack protocols. Because these tunnels have to be configured manually they are not very scalable, so this type of tunnelling is only suitable for permanent link. If a change in the network was to occur a manual tunnel does not change, there for they are also high maintenance. Encapsulation of the IPv6 header into the IPv4 header is taken place at the router. Where as 6-over-4 tunnels the encapsulation is taken place at the host. This might lead to a delay or bottle neck in performance over 6-over-4 network topologies. This is one question that could be answered by implementing the tunnelling technique in a network simulation.
