[Dibbler] DDNS and no forward update

Tomasz Mrugalski thomson at klub.com.pl
Fri Jan 6 18:19:02 CET 2012

On 02.01.2012 00:48, Thomas Wilhelmi wrote:
> Hello List,
> first of all I want to wish you a happy new year.
Thank you. The same to you all.

> I have a little problem with the dibbler-client on a Windows XP and
> BIND plus ISC DHCP on a Suse-Box. The version of dibbler is currently
> 0.8.1RC1 but I also tried the older versions.
> The problem is that the address-assignment is working correctly and
> the dynamic update of the reverse-zone as well. But the update of the
> forward zone is never tried (according to the logfile on Suse).
> Requests from other Systems (Win7, HP-Printer) are correctly updating
> the forward zone.
I'll look at this problem. Here are some comments:
1. ISC DHCP does not send back FQDN option. RFC4704 allows that, but
according to Section 6 of RFC4704 server MUST send back FQDN option if
client sent FQDN and requested FQDN in ORO. I believe that
dibbler-client does that. As server didn't return FQDN, dibbler-client
can't do the update on its own.

Note that forward zone can be updated by client or server. Your server
config indicates that it should be updated by ISC server.

That indicates that there are 2 interoperability problems here:
- lack of FQDN option in ADVERTISE and REPLY
- lack of forward DNS Update from server

I assume that ISC DHCP server doesn't like dibbler's fqdn option for
some reason. I will investigate this, but it seems that there's high
probability that server is at fault. However, you are talking to the
right guy. I happen to work for ISC and I'm partially involved in ISC
DHCP maintenance :)

> So what to do?
I will contact you off the list with extra questions.

Tomek Mrugalski
Dibbler author
ISC DHCP engineer

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