Ipv6 Over Ipv4 Tunnel - HP 4800G Series Configuration Manual

connection. In practice, the virtual interface that supports only point-to-point connections is called tunnel
interface. One tunnel provides one channel to transfer encapsulated packets. Packets can be
encapsulated and decapsulated at both ends of a tunnel. Tunneling refers to the whole process from
data encapsulation to data transfer to data decapsulation.
For related configuration about the dual protocol stack, refer to Dual Stack Configuration in the IP
Services Volume.
The 3Com Switches 4800G do not support NAT-PT.

IPv6 over IPv4 Tunnel

Implementation
The IPv6 over IPv4 tunneling mechanism encapsulates an IPv4 header in IPv6 data packets so that
IPv6 packets can pass an IPv4 network through a tunnel to realize interworking between isolated IPv6
networks, as shown in
The devices at both ends of an IPv6 over IPv4 tunnel must support IPv4/IPv6 dual stack.
Figure 1-1 IPv6 over IPv4 tunnel
The IPv6 over IPv4 tunnel processes packets in the following way:
1) A host in the IPv6 network sends an IPv6 packet to the device at the source end of the tunnel.
2) After determining according to the routing table that the packet needs to be forwarded through the
tunnel, the device at the source end of the tunnel encapsulates the IPv6 packet with an IPv4
header and forwards it through the physical interface of the tunnel.
Figure 1-1.
1-2