[Samba] Device ends up with multiple dns records and IP addresses

[Rowland Penny]

On Wed, 2021-10-20 at 11:40 +0100, Sebastian Arcus via samba wrote:
> I have a server with:
> 
> Samba 4.9.4 in AD mode
> Bind 9.14.2
> ISC Dhcpd 4.4.1
> 
> Samba is configured to use Bind for the dns back-end, and dynamic
> dns 
> updates from dhcpd->Samba->Bind are configured using the script at
> Samba.org
> 
> I have this strange situation where one of the printers has ended up 
> with 11 records in the dns back-end:
> 
> # host SEC001599AB9439
> SEC001599AB9439.ihs-uk.lan has address 192.168.51.184
> SEC001599AB9439.ihs-uk.lan has address 192.168.51.176
> SEC001599AB9439.ihs-uk.lan has address 192.168.51.179
> SEC001599AB9439.ihs-uk.lan has address 192.168.51.144
> SEC001599AB9439.ihs-uk.lan has address 192.168.51.241
> SEC001599AB9439.ihs-uk.lan has address 192.168.51.229
> SEC001599AB9439.ihs-uk.lan has address 192.168.51.231
> SEC001599AB9439.ihs-uk.lan has address 192.168.51.172
> SEC001599AB9439.ihs-uk.lan has address 192.168.51.177
> SEC001599AB9439.ihs-uk.lan has address 192.168.51.235
> SEC001599AB9439.ihs-uk.lan has address 192.168.51.182
> 
> In order to start troubleshooting, I can't get my head around which 
> software is not working properly. Is it the job of dhcpd not to allow
> a 
> same device to request a different IP, or is it the Samba script, or 
> Samba, or Bind? Which one should normally prevent this from
> happening? 
> Thank you much for any suggestions.

Sorry to be so long in replying.

Not sure what is going on here.

dhcp passes the full ipaddress to the update script e.g. 192.168.0.56

in the 'add' case, any existing 'A' record for the computer is obtained
by running 'samba-tool dns query'. If no record is found, a new one is
added. If an 'A' record that matches the supplied ipaddress is found,
then nothing happens. finally, if the ipaddress found by samba-tool is
different from the ipaddress passed to the script, then the existing
'A' record is deleted and a new one added.

Is there any way that the printer is updating its own record ?

Rowland