Keith Moore writes: > don't think upgrade; think coexistence. How do IPv4 and IPv6 coexist? Like ASCII and EBCDIC, perhaps? > As an engineer, the right thing to do is to transition away from NAT > (along with IPv4), so that eventually it can be discarded. I'm not aware of a smooth transition option; how does it work? And NAT is economically driven. Unless ISPs stop charging for extra addresses, it's hear to stay. > for some applications, it's simply impractical; for other apps, it's > much more expensive (in terms of added infrastructure and support costs) > to operate them in the presence of NAT. in either case the market for > those apps is greatly reduced, and the apps are more expensive as a result. It might still be cheaper than converting them to IPv6. > again, this doesn't really solve the problem - it only nibbles off a > small corner of it. NATs do harm in several different ways - they take > away a uniform address space, they block traffic in arbitrary > directions, they hamper appropriate specification of security policies, > and these days they often destroy transparency. Agreed, but they reduce the amount of money you must pay to your ISP each month by a factor of ten or more. > the reason this looks so complicated compared to NATs is that NATs never > really worked all of this stuff out. NATs started with a simple design, > pretended it would work well without doing the analysis, and have been > trying to fix it with bizarre hacks ever since that have only made the > problem worse. People will go to great lengths sometimes to save money. _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf