Comment by jerf
7 years ago
"(note: you may want local 128-bit virtual addressing for other reasons than accessing more memory)"
Yes, that's why IPv6 is as big as it is. We could fit pretty comfortably into 64 bits for a long time, really, if you assume we fairly tightly pack everybody in. 128 bits is really to give us some routing headroom, not because anyone seriously thinks we're going to use IPv6 on 2^128 distinct targets any time soon. (By the time we have a "galactic internet" it sure won't be using IPv6, not because it's bad or wrong but just because we're going to need something designed to handle the very different challenges involved.)
Intergalactic (or interplanetary even) networking is more likely to be UUCP like than TCP like, but that doesn't mean it won't need addressing, and that addressing might as well be IPv6. Maybe we can get packets larger than 1500 bytes though.