How does Windows decide the name of Ethernet LAN?

I have two WLAN SSIDs. One is operating at 2.4GHz frequency, and the SSID is "stratus24". Other is operating at 5GHz frequency, and the SSID is "stratus50". Both of these WLANs are bridged to the same Ethernet LAN. So, there are three ways to access the same network: via "stratus24" SSID at 2.4GHz, via "stratus50" SSID at 5GHz and via an Ethernet cable.

Now, if I connect my laptop (that has been previously connected to both stratus24 and stratus50 WLANs) via an Ethernet cable to the LAN, Windows 10 decides that the name of the wired network is "stratus24".

How does Windows 10 decide that the network is "stratus24"? Is it using the MAC address of the default router? Or the MAC address of the DHCP server? Both the DHCP server and the default router happen to be one and the same device, but that may not always be true.

An image of simultaneous 5GHz WLAN connection ("stratus50") and a LAN connection (which Windows 10 for some reason decides to be "stratus24"):

Solution 1:

I think I found the reason. I searched for "stratus24" in Windows registry using regedit and found that Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkList\Profiles\{41FBD081-E721-466D-89F9-2FE1FB37FEB6} has in ProfileName the "stratus24" string.

So, the next thing was to search for 41FBD081-E721-466D-89F9-2FE1FB37FEB6. I found it in Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkList\Signatures\Unmanaged\01(string shortened)05. It has ProfileGuid set to {41FBD081-E721-466D-89F9-2FE1FB37FEB6} and the DefaultGatewayMac is set to the MAC address of my default gateway!

Note the very long string after Signatures\Unmanaged\ was shortened because I'm not certain if it has my Wi-Fi password in an encoded form.

Based on this registry search, Windows is indeed using the default gateway MAC address to decide the name of the wired network. In my case, due to bridged operation of the WLAN device, the router bridges all networks (2.4GHz, 5GHz, Ethernet) together and the default gateway in all networks has the same MAC address.

Apparently, the fact that it selected "stratus24" and not "stratus50" was due to some random event, such as me connecting to the 2.4GHz network first before connecting to the 5GHz network, and now the profiles are forever in the order where the "stratus24" name is found before the "stratus50" name is found.

I do find a link in another directory (or whatever these things are called in Windows registry) in the registry to the "stratus50" string using the exact same default gateway MAC address. But apparently Windows finds the "stratus24" string first before finding the "stratus50" string.