DNS registration failure

[1001nights]

I have a TS-412 set up as an AD domain member. Every so often I get the following email notification:

Server Name: XXXXXX
IP Address: xxx.xxx.xxx
Date/Time: xxxx/xx/xx xx:xx:xx
Level: Warning
[Microsoft Networking] The NAS registration in DNS failed

which corresponds to:
Type Date Time Users Source IP Computer name Content
Warning xxxx/xx/xx xx:xx:xx System 127.0.0.1 localhost [Microsoft Networking] The NAS registration in DNS failed
in the System Log

Network connectivity is not impacted by the registration failure, nor is access to shared files.

Once the first one happens the situation is rarely, if ever, recovered, and the notification is repeated every retry, which seems to be once per hour, until I reboot the NAS. Then it will usually resolve itself.
I realise it's just a warning, but it's annoying nonetheless.

Is there any way of (preferably) resolving the registration failure, or of suppressing just this warning?
Thanks,

[schumaku]

Double check only the Windows AD DNS is configured on the NAS - no other DNS resolvers (being a local router LAN IP, ISP DNS server IPs, or public DNS IPs).

Does your DNS server permit dynamic updates from the NAS LAN IP address?

If the NAS is added to the DNS with it's A a matching PTR, I tend to state this warning can be ignored.

[1001nights]

Thanks for the reply.
The NAS gets the DNS server ip from the Domain Controller as DHCP server, which gives it primary and secondary DNS server ips. The primary is the domain controller itself and the secondary is the subnet gateway, in this case the router/modem.
The AD server does permit dynamic updates from the AD members, and none of them have any issues except for the NAS which only sporadically gets itself in this situation. Normally it works correctly as well.
Both the A and PTR records are valid, with the same timestamp, which interestingly is from before the NAS was rebooted.
I'm also pretty sure it's harmless, but it's sure annoying, and wrong.

Here's a dropbox link to the debug log from the DNS Server:

https://www.dropbox.com/s/386lrgkkw8hhr ... g.log?dl=0

and the NAS system log since the last firmware update and reboot:

https://www.dropbox.com/s/fcoge8jyngy6v ... g.csv?dl=0

if you fancy having a look at them. I can see that registration initially succeeds but at some point starts getting the error from the DNS server - there my expertise runs out.

[schumaku]

Very briefly browsing over the DNS log, aren't there typically duplicated records RCODE 5 (REFUSED) followed by updates with RCODE 0 (NOERROR) ?

Then, these updates seem to be roughly every hour. Is this potentially due to the DHCP refresh/renewal, or DNS config.

You might consider using a static IP config for the NAS for a test period, instead of DHCP.

[1001nights]

As I say, my knowledge of DNS updates is pretty limited. When it goes pear-shaped, I think the NOERROR messages are those received by the server, and the REFUSED are its responses.
I don't know why the update attempts are every hour - I thought it was the NAS retrying because of the previous error. It does correspond to the TTL in the update message, so for all I know it's what the NAS does normally. The DHCP lease is valid until 13/9/2016, so I don't think it's that.
I've examined the dns log further, and the point of first REFUSED (apart from just after rebooting the NAS, when there appears to be some auto-configged ip address causing errors) is at 1/09/2016 2:13:08 PM. The corresponding request at the same time seems to be identical to the previous one at 1/09/2016 1:12:20 PM, which succeeded. So that would sort of imply a DNS Server issue I guess.

[1001nights]

This is still happening - does no-one have any ideas?

[Communauto]

Hi, I also have this issue, but in my case, after I reboot the Qnap, I have to take it off the domain and join it back. This causes all my shares (which are given AD security groups access) to be unavailable. I have to reset all the security on all my shares.

Any Ideas???

[1001nights]

Hi Communauto,
Good to know I'm not completely alone. Qnap support wanted me to do exactly that, but because I didn't want to lose all the permissions I had to find a different solution.
Luckily, in my case I control the domain, so I removed the Qnap's DNS record from the domain's DNS server. The next registration attempt then succeeded.
I did this a couple of months ago and, touch wood, the issue hasn't appeared since.