Would it be possible to turn off or stop the inbound and outbound internet access of the QNAP QTS OS?
The goal is to only allow the NAS to be on an Internal LAN only with no access to the internet.
If it is not possible, I guess the only way to do this is by modifying the Network connection in the Firewall or the switch where it is connected.
There is always traffic for all sorts of update checks, online checks, ntp updates, etc.
If you want to block all outgoing traffic at the firewall level you can.
Yes, is there any such settings in QTS I can configure or this is external to the QNAP ?
Needs to be done on your gateway
You can use QuFirewall to configure your firewall settings.
For detailed instructions, please refer to this link:
How to Use QuFirewall | QNAP
Frequently asked questions about QuFirewall | QNAP
Let us know if this helps!