Perry Metzger writes: | You seem to dismiss link state offhand, but it | isn't clear that link state couldn't help out a lot here. (Neither is | it clear that it could but it appears to be an interesting area for | some experiments.)
Actually, I'm a fan of link state (ask Sue Hares or Dave Ward & company), but unfortunately there are lots of links in the Internet, so you have to hide them. If you don't, your graph-sort takes forever. This link-hiding implies lots of levels [Kleinrock & Kamoun], which means that either you have the same problem as Geoff in his most recent message (i.e., you have to do a lookup and keep the result along with the packet, or lots of lookups, or both), or you need a way to encode per-level information in the address such that it looks something like [<L1-address>.<L2-address>.<L3-address>...<LN-address>]. The problem is that 128 bits or about 64 bits, depending on what semantics you put onto the addresses, is not very much room to encode *anything near* the number of levels K&K hierarchical network optimality calls for in the Internet, let alone the sort of disjoint hierarchies and confederations thereof that one would want in a more policy-rich Internet. But, a variable-length field means new syntax means it's not IPv6 or IPv4 at all. Sean.