When an IPv6 host receives the 6to4-derived prefix by way of a router advertisement, the host automatically reconfigures a 6to4-derived address on an interface. The address has the following format:
prefix:IPv4-address:subnet-ID:interface-ID/64 |
The output from the ifconfig -a command on a host with a 6to4 interface might resemble the following:
qfe1:3: flags=2180841<UP,RUNNING,MULTICAST,ADDRCONF,ROUTER,IPv6> mtu 1500 index 7 inet6 2002:8192:56bb:9258:a00:20ff:fea9:4521/64 |
In this output, the 6to4-derived address follows inet6.
This table explains the parts of the 6to4-derived address, their lengths and the information they provide.
Address Part |
Length |
Definition |
---|---|---|
prefix |
16 bits |
2002, which is the 6to4 prefix |
IPv4-address |
32 bits |
8192:56bb, which is the IPv4 address, in hexadecimal notation, for the 6to4 pseudo-interface that is configured on the 6to4 router |
subnet-ID |
16 bits |
9258, which is the address of the subnet of which this host is a member |
interface-ID |
64 bits |
a00:20ff:fea9:4521, which is the interface ID of the host interface that is configured for 6to4 |