On Tue, 2012-10-16 at 22:13 -0500, Brian Wood wrote: > From: Jima > > > > > What have you done with or for IPv6? > > A week or so of IPv6 programming in the code here -- > http://webEbenezer.net/build_integration.html > . > > > No, 64-bit host addresses wouldn't "make more sense." If you're > > thinking of the IPv6 address space as 128-bit host addresses, you're > > doing it wrong. Think of it as 64-bit network addresses, each with > an > > irrelevant number of hosts. The lower 64 bits were engineered for > > autoconfiguration, and can be ignored for 90+% of scalability > discussions. > > An IPv6 packet header has the source and destination addresses -- > both > 16 bytes. The header is 40 bytes total. If the addresses were 8 > bytes > the header would be 24 bytes. I'm not sure what you mean by ignoring > the > lower 64 bits in scalability discussions. You might be confusing bits and bytes. An IPv6 address is 128-bits (16 bytes). The lower 64-bits of a single IPv6 address means the right half of an IPv6 address when reading it. Jima's specific reference was to SLAAC, see the wikipedia article on that for example. http://en.wikipedia.org/wiki/IPv6_address#Stateless_address_autoconfiguration