I am encountering a bizarre situation with our wired media server. The ethernet network works fine until it doesn't, resulting in an `Unidentified Network` and refuses to connect. I've tried resetting the network, repairing Windows 10, and even buying a new network card to install in one of the bays. None of these have worked and both network adapters result in the same thing: Unidentified Network.
This has happened once before, and I purchased the network card because of it. Before I was able to install it, however, the network finally started working again all was magically happy once more. So I kept the extra card for this situation in case it ever got wonky again and here we are.
I would appreciate any pointers on what could be causing this and any possible remedies.
I routinely have this happen on my Windows 10 PCs. It happens when my network server is offline for a while, and then I bring it back on line. The NIC on the PCs where it happens are setup as being on a "private" network, and when it happens, that same NIC on the various PC is then set by Windows, itself, as if it is on a "public" network. The permissions for NICs on public networks are restricted well over those that are on private networks. For some programs, Firefox, for instance, that do not use the standard Windows Network APIs to communicate with the internet, it makes no difference; that is, Firefox works perfectly whether or not the NIC is listed as on an "Unidentified Network."
Do you power off your media server from time-to-time?
What I reason is that Windows 10 (and perhaps other versions) take a snapshot of the computers on the network. If a server computer drops off the network (in my case, my server is my router, DHCP server, NTP server, Samba Server, Firewall, network storage, and internet gateway), Windows then assumes the computer is on a public network and changes the network permission level so that it cuts off network access to any and all programs that use the Windows Network API. Anything using that API has limited access to the network.
Once my server PC is back on-line, what I do as a quick way to get around this is to right-click on the network icon in the system tray, and select "Open Network and Internet Settings" Once in that, I select "Change Adapter Settings" under "Advanced Network Settings." Once that comes up, I right-click on the Ethernet Adapter and select "Disable." Then after the adapter changes status to "Disabled," I right-click on the adapter again, and select "Enable." Once the adapter comes back up, it changes status back to normal and away from "Unidentified Network."
Perhaps you have a bad cable somehow, but you've replaced the NIC so it is definitely not the NIC. Does your WiFi adapter use that NIC for internet connection sharing? If so, it is no surprise to me that the WiFi would also go down when the Wired NIC, itself, is in the "Unidentified Network" state.
My guess is that you do not have bad hardware, and this is strictly related to "enhanced security" that Microsoft implemented for network connections. This is my experience, but your situation might be different, and it is possible that you have a bad wire, or something.
When your wired NIC is in that state, you might be able to go into "Network and Sharing Center" and change the adapter to a "private network" adapter. I don't have instructions on how to do this, but an internet search should reveal exactly how this is done.