[arin-ppml] NAT444 rumors (was Re: Looking for an IPv6 naysayer...)

Chris Grundemann cgrundemann at gmail.com
Fri Feb 18 19:59:00 CST 2011

On Fri, Feb 18, 2011 at 16:48, Benson Schliesser <bensons at queuefull.net> wrote:
> I agree that it's an imperfect analogy, so I won't bother defending it. :)  But my point remains:  NAT444 is a deployment scenario, which includes a CGN element.  Other deployment scenarios that also include a CGN element will have the same issues, and perhaps more.  And, indeed, a number of "transition" (i.e. exhaustion) scenarios include a CGN.  Thus it is appropriate to focus on the root of the problem (CGN) rather than pointing at just one scenario that leverages it.

That I'll agree with. It seems to me that what's called for is an
expansion of the tests done for the draft in question to include
other, currently in-vogue, CGN/LSN technologies.

> So...  I agree that CGN is painful, relative to native connectivity and even relative to CPE-based NAT44.  But I'd like to understand why NAT444 is better or worse than other CGN-based scenarios, before I agree with that conclusion.

That wasn't the conclusion I drew, can't speak for others of course.
My conclusion is that CGN/LSN is broken, as evidenced by brokenness in
NAT444. I agree that a comparison of all (or some reasonable subset of
all) LSN technologies would be valuable, especially as folks may begin
to be forced to choose one. For now I stick with the ideal: Avoid if
possible. (Dual-stack early, dual-stack often?)

>> If we get dual v4+v6 connectivity quickly enough, we do not need LSN
>> (including NAT444).
> Amen, brother.  I guess I'm just pessimistic about the definition of "quickly" versus operationally realistic timeframes.

Fair enough, I still have hope. =)

> Cheers,
> -Benson


More information about the NANOG mailing list