Manual IPv6 Tunnels

Ipv6 tunnels ares used to interconnect 2 or more IPv6 network through an Ipv4 network.

A sample configuration is :

interface Tunnel 0
no ip address
ipv6 address 2001:CC1E:1:4545::5/64
ipv6 rip RIPng enable
tunnel source Loopback0
tunnel destination 150.1.4.4
tunnel mode ipv6ip | gre
end

Tunnel source and destination should be IPv4 adresses

The differents modes are

GRE : default mode (protocol 47), used tu encapsulate multiple layer 3 protocols
IPV6IP : less overhead than GRE (protocol 41) encapsulate only IPv6