Just when you thought you were beginning to understand IP networking the
rules get changed! IPv6 is the shorthand notation for version 6 of the Internet
Protocol. IPv6 was developed primarily to overcome the concerns in the Internet
community that there would soon be a shortage of IP addresses to allocate. IPv6
addresses are 16 bytes long (128 bits). IPv6 incorporates a number of other
changes, mostly simplifications, that will make IPv6 networks more managable
than IPv4 networks.
Linux already has a working, but not complete, IPv6 implementation in
the 2.2.* series kernels.