prerequisite not satisfied???

[Simon Hobson]

Anthony Ewell wrote:

>     In my /var/named/chroot/var/named/slaves/named-update-debug.log,
>I am getting the following error message:
>
>Sep 14 08:00:23.641 update: info: client 127.0.0.1#32770: updating zone
>'xxxxxx.local/IN': update failed: 'name
>
>not in use' prerequisite not satisfied (YXDOMAIN)
>Sep 14 08:00:23.653 update: info: client 127.0.0.1#32770: updating zone
>'xxxxxx.local/IN': deleting an rrset
>
>Sep 14 08:00:23.653 update: info: client 127.0.0.1#32770: updating zone
>'xxxxxx.local/IN': adding an RR
>
>Sep 14 08:00:23.653 update: info: client 127.0.0.1#32770: updating zone
>'255.168.192.in-addr.arpa/IN': deleting
>an rrset
>
>Sep 14 08:00:23.654 update: info: client 127.0.0.1#32770: updating zone
>'255.168.192.in-addr.arpa/IN': adding an
>   RR
>
>Is there something in my dhcpd.conf I am missing that is causing this?

This happens when the name already exists in the DNS, if you look at 
the DHCP logs you will see the update request being passed from which 
it will become obvious what it is doing.

As posted by David Hankins on 4th April :

>First we send a packet that looks something like this:
>
>	PREREQ:	[name] NONE A
>	ADD:	[name] IN A	a.b.c.d
>	ADD:	[name] IN TXT	"magic hashed string here"
>
>IF result is success, you're done.
>IF result is YXDOMAIN, you send another packet:
>
>	PREREQ:	[name] IN TXT	"magic hashed string here"
>	DELETE:	[name] ANY A
>	ADD:	[name] IN A	a.b.c.d


If the above succeeded, or it was skipped because the client will be 
doing updates then another update request is sent in to :
   delete any PTR records for the address
   add a PTR record for this address and host


The reason for the test is to prevent someone naming their client 
"BIGSERVER" and suddenly your very important server named BIGSERVER 
becomes inaccessible because it's DNS entries have been hijacked.

The answer is to manually delete the A records for the hosts 
concerned, they will get recreated when the client next renews.