[ILUG] dhcpd/bind/lookup problems

[David Ryan]

Ken,

Hmm - peculiar.  Let's start at the very beginning and see if we are
assuming something or missing something.

Your machine starts up and does a DHCP request on the network asking if
anyone out there will give it an address.  On the assumption that you
only have one DHCP server (check this) then it will reply to the request
with an address at least and also other details such as default gateway,
etc . . .

Assuming that your single DHCP server receives the request it will
process it against its rules and issue the address.  So here's where the
complication could come in.  It could be a problem with your ruleset.

I note from your original mail that the hostname of the problem machine
is 'acer.technobrat.net' and I also note that according to nslookup in
the real world technobrat.net is delegated to ns.host4u.net - this may
be part of your problem.  Have you recently tried to enable DDNS or
anything like that ?  Imagine this - your DHCP server wants to issue an
address and a fixed hostname to your client, but before it does this it
tries to update both the forward and reverse zones but isn't allowed to
update the forward since presumably host4u.net have allow-update ACLs on
their zones.  As a result your DHCP server refuses to issue the address
to your client.  This is just a theory but it makes sense to me.

Try creating a dummy zone (which doesn't exist in the outside world) on
your own machine and allow updates from 127.0.0.1 and then change the
fixed host name to something in the dummy zone and see if that works.

Otherwise try turning off DDNS if you have been playing with it and see
if that helps.

David

Ken Guest wrote:
> 
> On 18 Jul 2001 12:22:59 +0100, David Ryan wrote:
> > Have a look at - http://www.acmebw.com/askmrdns/bind-messages.html - for
> > an explanation of most of the weird messages that BIND generates.
> >
> > The entry for 'sysquery: nlookup error on ?' doesn't initially look like
> > it relates directly to your problem unless . . . your DNS server doesn't
> > have a zone file for 11.11.10.in-addr.arpa and then attempts to go find
> > it and then discovers it doesn't have any forwarder details and so
> > resorts to the root name servers and then discovers it doesn't even have
> > the zone file for the root servers either.
> >
> > Try the following :
> > nslookup[CR]
> > set type=ptr[CR]
> > 5.11.11.10.in-addr.arpa[CR]
> 
> ok. I didn't do this exactly (as I'd left the printout of your email
> behind in work), but I remembered the gist of it and found that
> a nslookup on 10.11.11.5 did work.
> So it seems that both reverse and forward lookups work fine from
> inside nslookup but not via ping or during a dhcp conversation.
> 
> any ideas?
> 
> ken.