In article <39B0343B.7FECFB0E@nominum.com>, "David R. Conrad" <David.Conrad@nominum.com> wrote:

Christian,

...

The point was a NAT'ed (masqueraded) network attempting to communicate with another NAT'ed (masqueraded) network. That does NOT work for the vast majority of people on the Internet.

Hmmm. If you never try something, can it be said to not work?

Until such a scenario becomes _far_ more commonplace that it is today, I doubt anyone (other than end-to-end purists and the folks who have been bitten) will care.

It is a basic principle often used in both protocol design and ethics that one cannot endorse a course of action that, if all were to follow it, causes undesirable consequences. If NAT is really the future, we must prepare for a world where NAT is carried to its logical conclusion; all sites use NAT. If that ultimate future is undesirable, then we should not even start down the road; we must conclude that NAT is not the future. It can, then, be at best an expedient hack. If we accept that peer-to-peer communication is a design goal of the Internet, then to make a convincing argument that NAT is the future, you must outline how two sites behind a NAT can communicate with each other conveniently. Otherwise: "That does not scale." -- Shields.