You may see a Windows machine lost network connectivity every 20 minutes. Or you may see the Windows machine lost network when you are connecting it via remote desktop protocol (RDP). I wrote an article to discuss virtual machine lost network connectivity problem on Emulex powered ESXi host. You may want to check out if you are running legacy ESXi and HPE hardware.
You may see following error if you check Application event log:
Source: Dot3Svc
Event ID: 15506
Description: Network authentication attempts have been temporarily suspended on this network adapter.
Or following error:
Source: Dot3Svc
Event ID: 15514
Description: Wired 802.1X Authentication failed.
There is a Reason Code in the event logs above. The code could be 327685, 327682, or 327626.
The reason is the Windows machine cannot get authenticated on an authentication enabled network. It could be certification file expired on the machine or server side, or something wrong between its.
Actually you can workaround this issue by disable “Enable IEEE 802.1x authentication for this network” option in Authentication tab in the network adapter Properties.
Please refer to Microsoft official document “advanced troubleshooting 802 authentication” if you want go deeper.