Please contact our online technical support engineer via the link below for help with this issue and attach the forum link and your forum ID as well:
https://salesiq.zohopublic.com/signatur ... 97d0be8892
These connections stem from the network connectivity detection mechanism in TOS 7.
Perfect - thank you so much for the explanation!EriChan wrote: ↑10 Aug 2026, 13:58These connections stem from the network connectivity detection mechanism in TOS 7.
The system implements a CheckNetworkBy204 service that checks internet connectivity approximately every 15 seconds. As part of this process, it performs DNS queries and connectivity checks against multiple well-known domains (such as baidu.com, google.com, cloudflare.com, etc.) to determine whether the NAS has an active internet connection.
This is expected background behavior used purely for network status monitoring. Hope this clarifies your concern!
To better assist you in confirming whether there are any abnormalities in the TOS system, please navigate to TOS > Technical Support > Issue Reports to generate and download the system report, then send the it to our technical support email at [email protected] via email, and attach the forum link and your forum ID as well.



I've had the same experience: heavy network activity after updating to DOS 7—not just to Baidu, Google, and Cloudflare, but also to myexternalip.com, ifconfig.me, and api.seeip.org—and all of this even though my system is running in “Security Isolation Mode.”EriChan wrote: ↑10 Aug 2026, 13:58These connections stem from the network connectivity detection mechanism in TOS 7.
The system implements a CheckNetworkBy204 service that checks internet connectivity approximately every 15 seconds. As part of this process, it performs DNS queries and connectivity checks against multiple well-known domains (such as baidu.com, google.com, cloudflare.com, etc.) to determine whether the NAS has an active internet connection.
This is expected background behavior used purely for network status monitoring. Hope this clarifies your concern!
After upgrading to TOS 7, you may be unable to access the system due to a full root directory or excessively high system resource consumption. Since the system is currently inaccessible, we cannot confirm the exact root cause.