ZyXEL Communications P-870HN-5xb User Manual page 361

On the ZyXEL Device, you can either set up a configured tunnel or an automatic
6to4 tunnel. The following describes each method.
Configured Tunnel
A configured tunnel is a point-to-point tunnelling mechanism that encapsulates an
IPv6 address with an IPv4 address. Routers (A and B) on both IPv6 networks (1
and 2) each must have an interface that connects to the IPv4 network (with an
IPv4 address). This allows the router to send and receive IPv6 data over the IPv4
network.
In this case, you must specify B's public IPv4 address on A (similarly, specify A's
public IPv4 address on B) in order for packets to arrive at the intended destination
through the IPv4 network.
Figure 217 Configured Tunnel Example
6to4 Tunnel
A 6to4 tunnel is an automatic tunnelling mechanism that provides connection
between IPv6 networks across an IPv4 network. To transmit IPv6 packets over an
IPv4 network, the IPv6 packets are encapsulated inside IPv4 packets.
The following figure shows a network example.
Figure 218 6to4 Relay Router Network Example
In a 6to4 tunnel, 6to4 routers (A and B in the example network) forward these
packets between IPv6 networks (1 and 2) over the IPv4 Internet. A 6to4 relay
router (C) connects to both an IPv6 and IPv4 network. A 6to4 relay router is used
P-870HN-5xb User's Guide
Appendix E IPv6
361