IPv4 address shortage? Really?

Steven Bellovin smb at cs.columbia.edu
Tue Mar 8 11:37:10 CST 2011

On Mar 8, 2011, at 11:21 09AM, Valdis.Kletnieks at vt.edu wrote:

> On Tue, 08 Mar 2011 08:43:53 EST, Steven Bellovin said:
>> It wouldn't -- couldn't -- work that way.  Leaving out longer paths (for many,
>> many reasons) and sticking to 64-bit addresses, every host would have a 64-bit
>> address: a gateway and a local address.  For multihoming, there might be two or
>> more such pairs.  (Note that this isn't true loc/id split, since the low-order
>> 32 bits aren't unique.)  There's no pathalias problem at all, since we don't
>> try to have a unique turtlevax section.
> Sticking to 64-bit won't work, because some organizations *will* try to
> dig themselves out of an RFC1918 quagmire and get reachability to
> "the other end of our private net" by applying this 4 or 5 times to get
> through the 4 or 5 layers of NAT they currently have.  And then some
> other dim bulb will connect one of those 5 layers to the outside world...
Those are just a few of the "many, many reasons" I alluded to...  The "right"
fix there is to define AA records that only have pairs of addresses.

		--Steve Bellovin, http://www.cs.columbia.edu/~smb

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