FQDN option

[ccantu at us.ibm.com]

Another thing to try is to let the DHCP server do as much of the work as
possible.  Having the server do the updates keeps me (the client) from
having to worry about dynamic updates.  I think I can check the S-bit in
the FQDN option to see if the server is capable of doing the updates.

---------------------- Forwarded by Carlos Cantu/Boulder/IBM on 08/02/2000
05:03 PM ---------------------------

"Dan Nicolae" <Dan.Nicolae at nospam.usa.xerox.com>@wrc.xerox.com on
08/02/2000 04:21:21 PM

Sent by:  news at wrc.xerox.com


To:   comp-protocols-dns-bind at moderators.isc.org
cc:
Subject:  Re: FQDN option




<ccantu at us.ibm.com> wrote in message
news:8725692D.00740AC8.00 at d53mta05h.boulder.ibm.com...
>
>
>
>
> Theory question:
> A DHCP client boots and only knows its machine name "mach1".  The DHCP
> server has been configured to dish out domain names, option 6
"warped.com".
> If the client sends the FQDN option with only "mach1" in its REQUEST
> packet, will the server fill in the rest of the name so the data in the
> FQDN option is returned as "mach1.warped.com"?
>
1. the client sends "mach1" in DHCPDISCOVER
2. the server sends back "warped.com" in DHCPOFFER
3. the client either sends "mach1.warped.com" in DHCPREQUEST or
4. the server confirms in DHCPACK that indeed the DNSUPDATE will be done
for
"mach1.warped.com" and not other domain

Of course, there are other combinations (e.g. the client ignores option 6,
or the server ignores the domain sent by the client etc.)

> I ask this because the client could have just asked for the option 6
domain
> name data and concatenated his machine name and domain name to then do
> dynamic DNS updates.  What's good practice? -- Use both so non-DDNS
> compliant servers can still give you good info with option 6?  -- Use
only
> one or the other, but FQDN preferably since it's exactly designed for
this
> dynamic update business?
>
>
>
I believe the best thing is to recognize both and have the client-FQDN
option take precedence over option 6.

Dan