On Sat, 15 Sep 2007, Paul Hoffman wrote: > Certainly. Every vendor who ties a license to an IP address has already had to > deal with customers who change IP addresses. I doubt that Bill's mentioning of > this practice was meant to say "therefore we can never do anything that would > cause renumbering". On the other hand, if you develop a system that forces enterprises to renumber, then you GUARANTEE that a large set of them will find a way to avoid (or at least take control of their own) renumbering, e.g. NAT --for many reasons that have already been cited in this thread, and some that have not been. Example: Fred mentioned that it would be nice to just use some form of host names, instead of addresses, but in the world I live in, MANY groups are geographically dispersed and want Traffic Disruption Appliances on each of their subnets to allow unrestricted flow among their *blocks* of addresses --they certainly would not want to either a) manage large lists of explicit host addresses *or* names, or b) change their complex firewall rules whenever someone sez let's do the Renumber Drill! (Is that perimeter protection model fundamentally flawed? Of course it is, just like NAT is. Both observations will not change the reality of their continued use. The question should be: what will? Note also, for fans of homogeneous networks and single network management stations, that a single AS may have hundreds of autonomous management domains within it. As others have said, this is not entirely a technology problem. -teg _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf