DHCPv6-4.1.mumble

[bmanning at vacation.karoshi.com]

On Wed, Jun 11, 2008 at 03:06:04PM -0700, David W. Hankins wrote:
> On Wed, Jun 11, 2008 at 09:35:41PM +0000, bmanning at vacation.karoshi.com wrote:
> > > if you wanted it to appear in a DHCPv6 packet.
> > 
> > 	er... not what I want.  I want to tell my v4 clients that 
> > 	it is ok to use a v6 address for DNS resolution.  They are
> > 	going to have v6 via other means - but RA/ND won't tell them
> > 	about their nameservers...  
> > 
> > 	when I want to do DHCPv6, I'll get there, and when I do,
> > 	I expect I'll want to tell my DHCPv6 clients about an
> > 	IPv4 address that they might want to use for DNS resolution.
> 
> then you're S.O.L, the ietf has never defined a v4 option that
> can carry ipv6 addresses for nameservers (or any other config
> option in dhcpv4).

	figured that out a -long- time ago.

> unless you define your own option codes and definitions such as
> in a "vendor-identified vendor option" (delimited by enterprise-id),
> vendor encapsulated options, or if you think you are a "site local
> administrator", you might consider "site local option codes."  but
> this presumes that you're writing the dhcp client software on all
> your nodes, explicitly to read and understand those options, which
> i suspect is not the case.

	necs'ity is the mother of invention.
	i've had to do worse in my time (still backporting
	crap ISC took out of BIND and removing crap they
	stuffed in - regardless of the IETF standards track... :)

> if you're doing stateless autoconf, and want to configure nameservers,
> consider if you haven't already "the O flag", stateless dhcpv6, and
> the previously quoted config snippet.

	that does look like the easiest option, run both v4 and v6
	dameons and hope like heck the end nodes don't fall all over
	themselves when presented w/ two, possibly conflicting sets
	of data.

	all i really want is DHCPv[foo] to give each node the ability 
	to have this in their resolv.conf

%cat resolv.conf

domain ep.net
nameserver 2001:0478:0006:0000:0230:48ff:fe22:6a29
nameserver 198.32.2.10


	i suspect that running dhcpv4 and dhcpv6 will push me into something
	like this:
	DHCPv4 runs "last" and I get:

%cat resolv.conf

domain ep.net
nameserver 198.32.2.10

	DHCPv6 runs "last" and I get:

%cat resolv.conf

domain ep.net
nameserver 2001:0478:0006:0000:0230:48ff:fe22:6a29

	I want -both- and ISC's DHCPv6 does not appear to be able to
	give it to me.  S.O.L. indeed.

--bill