> What is not > fixable is the fact that apps will break if you change an address out > from under them. heck, TCP breaks if you change an address out from under it, so it's hardly surprising that apps using TCP break under similar conditions. the TCP/IP architecture simply was not designed to tolerate hosts changing addresses. and no, IPv6 doesn't fix this. actually it's very difficult to fix at anything above layer 3. > This is a fact the app developers complaining about > the complexity of scoped addresses continually overlook. I don't know where you get that idea. I've been arguing against both scoped addresses and limited-duration addresses. It's just that there has been more attention paid to scoped addresses later. But absent drastic changes in the architecture, it's not sufficient that addresses have global scope, they need to be reasonably stable also. > The assertion is that all a network needs to do is change the > addresses in use when connecting. Never mind that every local use app > will break on every one of those events. That is not an acceptable > approach. agreed. But SL doesn't solve that problem, except in corner cases. better to have a comprehensive solution, or simply to expect addresses to be reasonably stable, than to impose SL.