Mark Smith wrote: > > I'm curious as to why you think this might be the case? > > From what I understand, fixed length addresses were chosen for a few > reasons (a) only CLNS had variable length addresses, verses every other > protocol that didn't (e.g. applelalk, IPv4, IPX etc.), so there was > much more limited experience with variable length addresses, (b) > people tended to use fixed length CLNS addresses within their > organisation anyway, to be operationally simpler and (c) it made > building hardware forwarding ASICS etc. much simpler. > > I can't see why IPv6 having variable length addresses would have > prevented people creating NAPT66 if /128s were allocated. >
Human hoarding instinct combined with old practices from the IPv4 days. You can see similar behaviour in areas where the PSTN uses fixed-length numbers (e.g. North America) versus those there the PSTN uses variable-length numbers (e.g. Germany). Yes, people tended to use fixed-length addresses within their administrative domain, but that is exactly the issue: the crossing of administrative domains. With a fixed-length address, each "owner" is going to try to control the address space as much as possible, even if it doesn't make sense. With variable-length addresses, each "owner" will chop off as much as they feel they need, and knowing they don't have to worry about it. -hpa -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------