Subject: Re: Future of TCP/IP?
To: Jeffrey Wheat <jeff@tad.cetlink.net>
From: Dennis Ferguson <dennis@Ipsilon.COM>
List: current-users
Date: 12/20/1995 21:27:47
> What plans are being made for the inevitable end of available ip addresses?
> From what I've been hearing from the internic and mci engineers, there are
> no class A or B IP's left, and there is a rapidly shrinking number of class
> C's left. 

I think you misunderstood.  I count 81 of the 126 usable class A networks
as being reserved, and about half of the 16k class B networks.  The thing
is that the Internic no longer assigns class A or B numbers to anyone
at all.  The best you can do is a variable-length block of class C addresses.

The reason for the allocation policy is that, while over half the address
space is unallocated, it is relatively easy to blow through the second
half of anything when you are coping with exponential growth as the
Internet is.  The policy of forcing people into relatively smaller
chunks of address space, and making them use the space more efficiently
by numbering more hosts with the smaller blocks, has dramatically dropped
the rate of consumption of the address space so it is likely to last
longer.  The class A and B numbers will be allocated when the C's run
out, but they'll be cut into the same small-size chunks that are handed
out now.  The network class is no longer relevant.

Not that the end isn't inevitable, it's just not as soon as it might have
been (in 1990 people were predicting that the address space would be gone
by now).

This seems like a strange place to be asking that question, though.

Dennis Ferguson