Constant DNS connections to qnap addresses

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1

Currently running Adguard Home DNS on my network and I’m seeing my NAS constantly send requests for the following domains:

auth.myqnapcloud.io
download.qnap.com
update.qnap.com
google.com
ncsi.qnap.com
  • I currently have the NCSI service disabled but I’m still seeing requests.
  • I understand the update service but about 20 times an hour??

Can anyone explain what’s going on? I have every report to qnap feature (like usage/stats) turned off accross the board but I’m seeing a total of around 100 requests from all these domains an hour. I also have no idea why the nas is trying to contact google.com?

*Nas: TS453-A

  • Firmware: QTS 5.2.2.2950
  • Single port setup using a virtual switch with NAT and DHCP disabled
2

My guess is update checks and RSS feed updates (App Store etc)

Check with QNAP support if you want a clarification from then (or just block them and see what stops working)

3

This is “normal” level of activity but QNAP is not being a good netizen.

The standard DNS setup on QTS uses a dnsmasq instance with caching disabled - so every time an application (e.g. QNAP store, connectivity checks, firmware update checker, etc.) needs to connect it fires a dns query. They also use a very low TTL on their DNS entries (60 seconds if I remember correctly).

In addition, if your NAS has more than one network interface it sends its DNS request to every interface. If you have IPv6 on your network multiply all the queries by 2 to account for the AAAA queries.

For starters it would make a difference if they enabled caching on dnsmasq and increased their TTLs to something like 30 minutes or more.