On Thu, Mar 30, 2006 at 07:08:51PM +0200, Anthony G. Atkielski wrote: > Steve Silverman writes: > > > The problem with allocating numbers sequentially is the impact on > > routers and routing protocols. > > The problem with not doing so is that a 128-bit address doesn't > provide anything even remotely close to 2^128 addresses. > But this has been known all along. It's a feature, not a bug. If we "throw away" the last 64 bits we are left with 2**64 addresses, which is obviously what was intended from the beginning. Allocating to ISPs on /48 or so boundaries then maps roughly to ipv4 /16s which are often handed out now. If a /8 in v4 space gets parceled out by the registries in a matter of months, a /40 in v6 should last the same. Following that logic, a /32 in v6 space should last as long as /0 in v4 space. The current v4 /0 has lasted for some time now, it's difficult to envision a time where we would be burning through space so fast that /32s in v6 space wouldn't last months, if not years. But for argument's sake, let's say a /32 lasts one day at some point in the dim future. This gives us 2 ** 32 days before we run out. not too bad for those of us not realistically having much of a chance to live beyond 2 ** 15 or so. If we "throw away" additional bits for other engineering purposes the number of days would be 2 ** (32 - wasted bits). If we waste a full half of those bits bits we're down to 2 ** 16 days (about 180 years). Again, that assumes we'd burn what is equivalent to a v4 /0 every single day for 180 years. Maybe it will become a problem when everyone has addressable nanocytes in their bloodstream. But I have a hard time seeing how it could be described as shortsighted. > In that case, assign addresses to points in space, instead of devices. > An office occupying a given plot of land will have an IP address space > that is solely a function of the space it occupies. Routing would be > the essence of simplicity and blazingly fast. > Routing doesn't (and will never) work that way. Much like with airlines, the cost of a path is more complex than mere distance. > > IMO one problem of the Internet is that it isn't hierarchical enough. > > Consider the phone system: country codes, area codes ... This makes > > the job of building a switch much easier. I think we should have > > divided the world into 250 countries. Each country into 250 > > "provinces". Yes, it would waste address space but it would make > > routing much easier and more deterministic. > > With a variable address length that can extend infinitely at either > end, the address space would never be exhausted. That's how > telephones work. > That would be an alternative, certainly. I'm not sure how excited to get about a 1 byte payload needing 1000 bytes of header, but I'm sure it's possible. Is it worth throwing away the current post-v4 solution? Certainly something to consider over the next 180 years. Austin _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf