Appendix F IPv6
AMG1302-T11C User’s Guide
285
Figure 179
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 180
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 to forward packets between 6to4 routers in an IPv4
Internet and an IPv6 device (
Z
) on the IPv6 Internet.
To transmit packets, a 6to4 address is used with a special IPv6 prefix of
2002::
to encode a given
IPv4 address. A 6to4 address has the following format:
2002:IPv4 address:subnet ID:host ID/64
For example, if you have an IPv4 address of 192.168.1.1 (first converted to binary notation and then to
the colon hexadecimal representation of
c0a8:0101
), then the 6to4 addresses is
2002:c0a8:0101::1/
64
.
