Subject: RE: [dhcwg] Re: WG last call ondraft-ietf-dhc-dhcpv6-opt-dnsconfig-02.txt

From: Pekka Savola <[email-masked]>
Date: Fri, 21 Feb 2003 11:29:54 +0200 (EET)

On Fri, 21 Feb 2003, BELOEIL Luc FTRD/DMI/CAE wrote:
> > > Implementation decision, but I guess typically the results of the
> > > latest query take precedence.  I don't see a problem here, myself.
> > 
> > Unpredictable behavior. Difficult to debug.
> > 
> > 	 - Alain.
> 
> Good remark! I understand the point/issue if IPv6 provider is not the
> same as IPv4 one. By that way the node may not have the same global
> vision of the Domain Name System! 

I'm having a difficulty seeing the point.  A similar situation happens if 
the user has manually configured a few nameservers in /etc/resolv.conf and 
then runs either DHCPv4 / DHCPv6.

Is it IETF's business to specify whether or not (and if so, how) the
entries should be overwritten, prepended/appended, etc. ?  Is this done
now with DHCPv4?

I'm not so sure, but something like "DNS servers configured through this
option should take precedence if some existed beforehand" would be
acceptable to me Note *no* RFC2119 upper-case keywords.

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings

--------------------------------------------------------------------
IETF IPng Working Group Mailing List
IPng Home Page:                      http://playground.sun.com/ipng
FTP archive:                      ftp://playground.sun.com/pub/ipng
Direct all administrative requests to [email-masked]
--------------------------------------------------------------------

---

From: Mika Liljeberg <[email-masked]>
Date: 22 Feb 2003 13:03:00 +0200

On Fri, 2003-02-21 at 11:07, BELOEIL Luc FTRD/DMI/CAE wrote: 
> > Some may scream at this idea, but couldn't we pass an IPv4-mapped 
> > address
> > in there? The DHCPv6 client could recognize this special format
> > to mean this is actually a v4 address?

I think this is a good idea.

> I feel ill at ease with such a solution. How your DHCPv6 client, running
> a node, is aware that there is an IPv4 stack enable on that same node ?
> If it is not, v4-mapped addresses could be harmfull, couldn't they ?

Not really. Why would a network administrator advertise IPv4 DNS servers
on a network with IPv6 only nodes?

Even if there are some IPv6 only nodes on the network, the host resolver
on those nodes will simply try to use the IPv4-mapped address and fail,
and move on the the next one as it would do with any malfunctioning DNS
server.

I don't think the DHCP client has to care whether IPv4 is enabled on the
node (although it could attempt to check that). All it has to do is
configure the DNS addresses and let the host resolver take it from
there.

	MikaL