IPv6 is a newer numbering system that
provides a much larger address pool
than IPv4. It was deployed in 1999 and
should meet the world’s IP addressing
needs well into the future.
The major difference between IPv4 and
IPv6 is the number of IP addresses.
There are 4,294,967,296 IPv4
addresses. In contrast, there are
340,282,366,920,938,463,463,374,
607,431,768,211,456 IPv6 addresses.
The technical functioning of the Internet
remains the same with both versions
and it is likely that both versions will
continue to operate simultaneously on
networks well into the future. To date,
most networks that use IPv6 support
both IPv4 and IPv6 addresses in their
networks.