[75547] in North American Network Operators' Group
Re: Important IPv6 Policy Issue -- Your Input Requested
daemon@ATHENA.MIT.EDU (Iljitsch van Beijnum)
Mon Nov 15 18:55:11 2004
In-Reply-To: <Pine.CYG.4.58.0411151607130.1720@citabria>
Cc: NANOG list <nanog@merit.edu>
From: Iljitsch van Beijnum <iljitsch@muada.com>
Date: Tue, 16 Nov 2004 00:53:51 +0100
To: Adi Linden <adil@adis.on.ca>
Errors-To: owner-nanog-outgoing@merit.edu
On 15-nov-04, at 23:10, Adi Linden wrote:
> Aren't unique site locals associated with the mac address?
Not really. Unique site local addresses as such don't have anything to
do with MAC addresses. However, most IPv6 addresses (including,
presumably, unique site locals when they are deployed) contain a MAC
address in the bottom 64 bits. This happens when stateless
autoconfiguration is used: routers broadcast (well, multicast) the top
64 bits and hosts fill in the lower 64 bits with a unique value. This
was the MAC address (if available) until privacy advocates came along
and now there is also RFC 3041 which uses random numbers for this.
Note though that it is by no means required to use stateless
autoconfiguration: you can set the address(es) manually, or you can use
DHCP for IPv6. Also note that (AFAIK) of the major OSes and out of the
box, only Windows supports RFC 3041, and Windows and MacOS don't (yet?)
come with DHCPv6 support, and it doesn't look like it's easy to add it
yourself (like in the *nix world) either.
