Subject: Re: Things I want to see in DHCPv6

From: Francis Dupont <[email-masked]>
Date: Thu, 31 Aug 2000 17:48:12 +0200

I think I shall not be very politically correct because I come from
the IPv6 world and *not* from the DHCP one (in fact I don't believe
in DHCPv4, I always asked for static addresses at IETF meetings :-).

The first point is we have two very different ways:
 - make a DHCPng for both IPv4 and IPv6
 - make a statefull autoconfiguration protocol for IPv6
There are technical difficulties with the first option and the second
is about something which has been needed in the IPv6 community for *years*
then I'll arbitrary focus on the second path.

 * there is no good reason to copy DHCPv4 in DHCPv6 then my first proposal
   is to change the name in order to make this point clear. I'll use
   the name SFAC.

 * I insist: DHCPv6 is a wrong name because in IPv6 there is already
   a dynamic host configuration protocol. SFAC is the stateful part,
   ie. it does roughly the same thing but the state is not distributed
   in nodes, the state is retained and managed on a few servers.

 * SFAC doesn't need an unique identifier per interface because it has
   already one, the interface ID derived from EUI64. The EUI64 is not
   bound to the interface hardware, look at the nearest sparc if you need
   a proof. Of course if you have no IEEE-like hardware (using PPP for
   instance) it is good to use a stable storage for an identifier (I'd
   like to know where I can get the DHCPv4 'client identifier' if there
   is no stable storage available). This will work even it doesn't keep
   an immediate advantage of EUI64: global unicity (uniqueness?).

 * don't joke about the privacy draft, I don't believe it will be use
   (because it is simply not usable :-) in an environment where addresses
   are assigned by a management tool like a SFAC daemon.

 * I think SFAC has two major modes. In the first one it is used as a
   remplacement of stateless autoconfiguration, ie. it assigns exactly
   the same addresses, ... In the second mode it is used as a registration
   service, nodes will build their addresses as usual (ie. prefix+iid)
   but registered them to a SFAC server before using them.

 * an example for the second mode: the site is separated from the Internet
   by a firewall (filtering box, not a N..!). A packet can go through
   the firewall only if it has a registered address, then if someone
   blindly connects its laptop on a site subnet then he won't gain
   the priviledge to communicate with the outside...

 * there is already at least another (than IPv6 address) example of
   a releasable resource then keep them!

 * if we need to remove things, first kill the crazy POSIX time stuff.
   if we need to remove other things, delete extensions which can be
   easily done by the service location protocol. I think only the DNS
   stuff is useful because SFAC is a good DNS dynamic update agent.

Regards

[email-masked]