Only 5x IPv4 ... WRONG! :)

Michael Dillon wavetossed at
Thu Oct 21 16:46:50 CDT 2010

> Couldn't let this one slide...
> Bits grow exponentially.  Saying IPv6 is 4x IPv4 isn't really accurate
> unless you're counting bits.


IPv6 is 128 bits and IPv4 is 32 bits.

Lots of folks can get an IPv4 /16 which gives then 16 bits to play
with for subnetting. But only network operators can play this game and
get this kind of allocation.

Switch to IPv6 with its /64 Interface Identifier and every mom and pop
can get a /48 which gives them 16 bits to play with for subnetting. In
fact, their ISP with a /32 or better, also gets 16 bits for subnetting
no matter how small their business. Riches upon riches for everyone to
use as they please. We are all oil millionaires with IPv6 and must
learn to forget the hardships of living in the dusty dunes of IPv4.

There are enough bits for almost everyone to build a network that
makes the most sense for their physical topology without worrying
about growth, because you can leave space for growth at every level of
your addressing architecture. It is only the very largest
organizations who still have to be careful not to run out of
subnetting bits because they can reasonably expect to justify a /20
today, but require a /18 in 5 years of growth and acquisition. On the
other hand, they tend to have better people and already know how to
manage IPv6. There is not much that we can teach them in this
discussion, but the smaller network operators and enterprise folks
would do well to pay attention and shift their thinking out of the
IPv4 world and into the abundant world of IPv6.

In the IPv4 world, people had to deal with the results of their own
mistakes. In the IPv6 world, it will be your grandchildren and
great-grandchildren who will have to deal with your mistakes and they
will thank you for leaving them some real challenges and not trying to
engineer away their choices.

--Michael Dillon

More information about the NANOG mailing list