There have been many predictions over the years
about IPv6 migration, but the fact is that the IPv4
workarounds that have been developed in the
meantime have been pretty good. It could be that
despite being a superior solution to the address
scarcity issue, IPv6 may never displace IPv4 and its
work-arounds. To underscore this point, look back
at the chart at the beginning of this section. Here
we are in 2007, with only limited deployments of
IPv6, and with many more devices on the Internet
than anticipated back in the late 1990s, but IPv4
keeps chugging along.
Several factors may finally cause the transition—
first as IPv6 “islands” connected with IPv4 networks,
and then finally into end-to-end IPv6 networks.
These factors include the U.S. federal government
mandating that its networks must be IPv6-capable
by a certain date, Microsoft adopting IPv6 into
Windows starting with Vista, and Japan adopting
IPv6 as its country network addressing standard.
At a minimum, it is important for network administrators
and companies to understand IPv6 and its
potential impacts so that they are prepared if and
when the transition occurs. 40