Re: proposal for a compromise on DNS discovery

[Doug Barton <DougB@DougBarton.net>]

On Tue, 29 Jul 2003, Tim Chown wrote:

> On Tue, Jul 29, 2003 at 10:55:01AM -0700, Doug Barton wrote:
> >
> > 1. In every situation where RA DNS announcements are proposed, dhcp is a
> >    better solution.
>
> But will every device have a DHCPv6 (or DHCPv6 Lite) server on link?

This has been asked an answered numerous times. In addition to the
overly simplistic "yes" that this overly simple question deserves,
please note the rather precise way that I've framed my statement. For
every situation that you can posit where RA DNS "might be a good idea,"
my response is, "dhcp is a better idea."

The fact that dhcp is already nearly impossible to avoid, even if you
wanted to, simply adds strength to my argument.

> For those that do, one might ask "why bother with stateless autoconf?"

ENONSEQUITUR

> and of course many sites will wish to keep using DHCP(v6) as a policy
> choice. But for networks without DHCP on link, the RA method is an
> alternative.

See above.

> Perhaps you can elaborate on your view of "better" to help the resolution
> of this discussion along? :)

I have done this in the past, but the summary is that dhcp already
provides the mechanism to do what RA DNS announcements would, plus all
the other things that are actually needed to make a client that needs
DNS resolution functional. Thus, it's pointless to make an incomplete
implementation of something from scratch when a complete implementation
of a complete solution already exists.

<selfish state=on>
Also, speaking as a client (freebsd) implementor, I don't want to have
to fuss with "maybe RA exists, and maybe it doesn't," given that the
solutions are already in place for dhcp.
<selfish state=off>

> > 2. RA DNS announcements are an ugly feature creep for RA, and should not
> >    be implemented.
>
> The spec for Router Advertisements allows for additional options to be
> specified, so this was considered possible when the spec was done.

I didn't say, "RA should never be added to." I said THIS is an ugly
feature creep for RA. Primarily because the IP(s) of the resolver(s) are
mostly useless without the search string, and then of course you'll be
needing to add the netbios name server IPs, etc. etc.

There is no point in starting down this road (and lots of reasons not
to).

Hope this helps,

Doug

-- 
Angel:  We need you to distract the vampires.
Buffy:  Right.
Xander: What are you going to do?
Buffy:  I'm going to kill them all. (Walking away)
	That oughta distract them.
  "When She Was Bad" - Buffy the Vampire Slayer, Season 2 Episode 1
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