Re: AP wire 'slams' IPv6 autoconfig

Kragen Sitaker (
Tue, 12 Oct 1999 08:40:17 -0400 (EDT)

Rohit writes:
> Sigh... I know Ted talked to a lot of people who made it quite clear
> this is a harmless stage of autoconfiguration.

According to _IPv6: The New Internet Protocol_ by Christian Huitema,
the stateless autoconfiguration process that is expected to be used by
most IPv6 hosts puts the IEEE-802 address into all of the host's
addresses, including the provider-based or geographically-based
addresses. There's a stateful configuration process using DHCP that
lets you assign addresses however you want, but the book implies that
most people won't use it because it's a pain in the ass.

The book is dated 1996. Have things changed? I guess I should read
the latest RFCs.

(I must confess I didn't think about the privacy implications of this
when I first read the book.)

> My own point was that the IP->MAC mapping is already public
> information -- that's the whole point of IP routers, to maintain that
> reverse lookup.

Well, not just IP routers, but every host needs to know the MAC
addresses of the hosts on its local network it wants to talk to.
That's what ARP and (part of) IPv6 neighbor discovery are for.

But that doesn't make it "public information". Only machines I'm
directly connected to can suss my MAC in IPv4 -- machines that have to
know it anyway.

> A panicky smith just seems like a better story, doesn't it?
> Especially since guids in OLE ended up such a hot-button.

I'm sure Marc Rotenberg of EPIC isn't "panicky".

<>       Kragen Sitaker     <>
Tue Oct 12 1999
28 days until the Internet stock bubble bursts on Monday, 1999-11-08.