[e2e] Mystery

Steve Deering deering at cisco.com
Sun Apr 29 14:28:32 PDT 2001

At 11:26 PM -0400 4/28/01, David.Eckhardt at cs.cmu.edu wrote:
>If memory serves me, one of the myriad forms of IPv6 address is
>some constant prefixed to a 48-bit MAC address, which can somehow
>be parleyed into a globally routable address.


It's the MAC address that is constant, not the prefix (i.e., high-order
part of the address).  The high-order part of a node's IPv6 address(es)
depends on what subnet(s) the node is attached to, and is discovered
automatically by the nodes.

By the way, this approach to address autoconfiguration is an old idea, 
which I first saw in Xerox's XNS (which mutated into Novell's IPX),
and was also defined for ISO's CLNP.

The implication in the Sony announcement that a device might get an
IPv6 address "for life" is the latest misconception that we (the IPv6
design community) are having to counter -- we recently just barely
stopped an IPv6-related press release from the European Commission
that was to include language about permanent IP(v6) addresses becoming
a human right(!).  Maybe someday when we figure out how to do flat
routing to all devices in the Internet...  (Until then, we'll have
to limit the right of humans to having only a DNS name for life.
Or something.)


More information about the end2end-interest mailing list