Hi David, On Sun, 16 Oct 2005 16:49:25 -0700 (PDT) David Barak <thegameiam@yahoo.com> wrote:
<snip>
I'd change the allocation approach: rather than give every customer a /64, which represents an IPv4 universe full of IPv4 universes, I'd think that any customer can make do with a single IPv4-size universe, and make the default end-customer allocation a /96. ISPs could still get gigantic prefixes (like a /23 or something), to make sure that an ISP would never need more than one prefix.
If we're going to do that, we may as well also start reclaiming those 48 bit MAC addresses that come with ethernet cards. After all, nobody would need anymore than say 12 to 13 bits to address their LANs. Hmm, so what do 48 bit addresses give us that 12 bits don't ? How about convenience. It is convenient to be able to plug in an ethernet card, and, excepting the very rare occasions when a manufacturer has stuffed up, be assured that you can just plug it in and it works. No jumpering, no maintaining a LAN address registry per segment, no address collisions, or at least extremely rare ones.
From what I understand, it is considered that 48 bit MAC addresses will be too small for our convenience needs of the future, so IEEE have invented 64 bit ones (EUI-64s).
Wouldn't it be nice to the same sort of convenience in a new layer 3 protocol that we've had since 802.3 was first published (and since I started working in networking 1993) ? I'd like it, and I'm willing to pay a few bytes in the src and dst addresses in my layer 3 protocol header for it. /64s in IPv6 for multi-access segments (i.e. everything other than single address loopbacks) is convenient and useful, and I think should be kept. Regards, Mark. -- The Internet's nature is peer to peer.