--- David Conrad <drc@virtualized.org> wrote:
Wrong issue. What I'm unhappy about is not the size of the address - you'll notice that I didn't say "make
On Oct 17, 2005, at 10:39 PM, Paul Jakma wrote: the whole address
space smaller." What I'm unhappy about is the exceedingly sparse allocation policies You can allocate to 100% density on the network identifier if you want, right down to /64.
I believe the complaint isn't about what _can be_ done, rather what _is being_ done.
Yes and yes. I am certainly complaining about what *is* being done. See below for my bigger issue.
The host identifier simply is indivisible, and just happens to be 64bit.
I've always wondered why they made a single "address" field if the IPv6 architects really wanted a hard separation between the host identifier and the network identifer. Making the "address" a contiguous set of bits seems to imply that the components of the "address" can be variable length.
Now we're cooking with gas: what we've learned from MAC addresses is that it's really nice to have a world-unique address which only has local significance. The /64 "host identifier" is a misnomer: there are folks who use /127s and /126s for point-to-point links, and there are all sorts of variable length masks in use today. The whole reason for a /64 to be associated with a host is to have enough room to encode MAC addresses. I ask again - why exactly do we want to do this? Layer-2 works just fine as a locally-significant host identifier, and keeping that out of layer-3 keeps everything considerably simpler. -David Barak- -Fully RFC 1925 Compliant- __________________________________ Yahoo! Music Unlimited Access over 1 million songs. Try it free. http://music.yahoo.com/unlimited/