Subject: RE: Sequentially assigned IP addresses--why not?

From: "Corzine, Gordie" <[email-masked]>
Date: Thu, 10 Aug 2000 17:14:49 -0400

Using the IP address, you index into a table with 100 M entries, pick up an
index into the 75K entry routing table.  You now have two tables that
require maintenance, that's all.  If customer changes ISP, their entry in
the first table is changed.  Link is down, the second table's mechanisms
handle it. Use a 64 bit processor architecture, memory is cheap.
Re-architecting the Internet is going to become all but impossible.

Its a matter of separating routing from identification.

Look, my days as an engineer are a distant memory, so I won't try to work
this out in detail.  Maybe there are irrefutable reasons why this can't be
done, but I do believe the current architecture will lead to premature
exhaustion of the address space.

Gordie

From: Steven M. Bellovin 

>
>Wouldn't it be better by far, to assign new addresses from 000...1, and map
>to routing information however we may code it?  The memory and processor
>steps required would be trivial compared to the agony of running out of
>space again.

The problem is that we (as a profession) don't know how to do that.  We 
have to make routing scale, and that demands aggregation, which 
in turn demands structured addresses.

Look at it this way.  We have about 75K routes in the "default-free 
zone" now.  If we just assigned addresses sequentially, we'd need a 
route for every endpoint.  There are what, 100,000,000 nodes today, and more

tomorrow?  We can't handle 3 orders of magnitude increase in the size 
of that table, let alone what it will be in a few years.

---

From: John Kristoff <[email-masked]>
Date: Fri, 11 Aug 2000 09:51:39 -0500

> exhaustion of the address space.

It will take far longer to design and deploy something that is so
technically elegant it solves all problems and pleases everyone.  At
some point you simply have to move forward.  To do nothing can be far
more dangerous (as proven by the disdain for NAT).  Can IPv6 be worse
for the net than NAT?  If premature depletion of IPv6 addresses is the
biggest problem IPv6 ends up encountering I'd say the net is in good
shape.  It's probably more likely that new problems no one had
considered will arise.  I see rough consensus, move forward.

John