[Samba] Dynamic DNS updates from Windows 10 workstations

[Peter Milesson]

On 2021-04-07 20:27, Rowland penny via samba wrote:
> On 07/04/2021 19:12, Peter Milesson via samba wrote:
>>
>>
>> On 2021-04-07 19:23, Rowland penny via samba wrote:
>>> On 07/04/2021 17:41, Peter Milesson via samba wrote:
>>>> Hi folks,
>>>>
>>>> I just finished setting up a secondary AD DC using Louis' packages 
>>>> (thanks a lot Louis) on Debian Buster. No real problems or serious 
>>>> headaches there, DNS, DNS replication, Sysvol replication all 
>>>> working. Both DCs use the Samba internal DNS server.
>>>>
>>>> I noticed that there are many extremely old and stale DNS A records 
>>>> for Windows 10 workstations getting their IP addresses from a 
>>>> dnsmasq DHCP server (just using the DHCP part, not DNS). On all 
>>>> workstations, registration of the IPv4 address with DNS is enabled. 
>>>> It's absolutely plain that no DNS records are updated. How can I 
>>>> get the dynamic update in the DNS servers working?
>>>>
>>>> Best regards,
>>>>
>>>> Peter
>>>>
>>>>
>>>
>>> Windows clients are supposed to be able to update their own dns 
>>> records, so I would suggest looking at them, there is nothing built 
>>> into Samba to update dns records.
>>>
>>> Rowland
>>>
>>>
>>>
>> Hi Rowland,
>>
>> Maybe I've got things wrong, but what entity is responsible for 
>> updating the A records in the Samba DNS servers, 
>
>
> It is either the Windows clients themselves, or the DHCP server. The 
> DHCP server must be capable of updating the dns records directly (I 
> don't know any DHCP server capable) or it must be capable of running a 
> script when the dns data is committed (I only know of one capable of 
> this, the isc-dhcp-server).
>
>> and when? Just an example, I have got a Windows 10 workstation with 
>> the following data in the AD DNS entry:
>>
>> Name: p2012022901
>> Type: Host (A)
>> Data: 172.16.10.184
>> Timestamp: 4/7/2019 11:00:00 AM
>
>
> That doesn't look like it has changed since 2019
>
>>
>> The workstation is used every day, restarted frequently, having the 
>> latest Windows updates, but the IP address for the A record is wrong, 
>> currently it is 172.16.10.185 (from the DHCP server). Shouldn't the 
>> Windows 10 workstation register itself with the AD DNS with the given 
>> IP address? The tick box is checked for the IPv4 settings.
>
>
> Is there anything else getting in the way, Firewall ? GPO ?
>
>>
>> If my questions seem stupid or based on lack of knowledge, please 
>> correct me, so I can learn from this and get things right.
>>
>
> Not stupid, might be lack of knowledge, but if it is, I am as guilty 
> as you are, I don't use many Windows machines, and the ones I do use, 
> all have fixed IP's.
>
> Rowland
>
>
Hi Rowland,

Thanks for your advice. The timestamp is really from 2019 almost exactly 
2 years old. There are just a few very basic GPOs applied. The other 
workstations use the same GPOs. Some of the workstations update the data 
correctly, and a few not. The dnsmasq DHCP server which I use, is not 
able to handle any DNS updates, so that task is up to the Windows 
workstations.

I will try to unjoin the offending workstations from the domain and join 
them again. If that does not help, I can always try to make clean 
installations of Windows. The offending workstations are mostly older 
(except one), originally upgraded from Windows 7, previously used in a 
Samba NT4 domain. I don't know if it's a long shot, but may really be 
the underlying cause.

Thanks for your input.

Best regards,

Peter