
Chapter 2 • What’s Wrong with IPv4? 21
Most of the people who oppose IPv6 believe the status quo, IPv4, is just fine
for now and perfectly adequate going forward as long as proper precau-
tions are taken, and there is no good reason to change. As a result, there is
no other candidate internetwork protocol capable of supporting the kind
of growth the Internet has long experienced. If you don’t like IPv6, it’s
because you don’t want to change from IPv4, not because you like some
other option.
IPv6 is the only practical and sustainable option.
At the same time, IPv6 will likely never replace IPv4. It must somehow
coexist with IPv4 as it gains ground. There ...