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That might seem like a simple question but it isn't. A USB-Eth adapter creates over 200 entries in a Win10 registry. None of them have the MAC address as a value; the adapter does get a GUID and the MAC address isn't found tied to them either.
The MAC address is shown with getmac and confirmed with Wireshark. Then it gets weird. That value IS found in the registry but NOT for Ethernet adapters. For example there is a key HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices with multiple values that appear to be a log of USB things plugged in.
For example the MAC from getmac is 74-DA-DA-33-E1-C0. Matches what Wireshark says for an ARP. In the Registry, it's in key HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices, value 6 name \??\Volume{e7701cc6-de87-11e7-97e1-74dada33e1c0} and the hex block identifies this as a the Kingston USB, or value 12 with name \??\Volume{a99c3b08-2c75-11e8-9807-74dada33e1c0} as a Sony floppy drive (yup, there was one).
The same happens when I search for the MAC address of another interface so this isn't just a string coincidence. The other MAC is a Dell Ethernet port. The registry is using these more like a connection point. Are MACs anywhere in the registry or only read from the adapter when needed?
Andy-1
Posted 2018-03-26T20:02:38.347
Reputation: 1
There is nothing preventing them from being stored in the registry, and the OS is not the only system that may store them there. Any application with access to the hardware and the registry may be able to read MAC addresses, and if they desire, record these in the registry. So, there is no way to answer your question as it is currently written. Why are you asking this? Is there something else you're trying to accomplish? – music2myear – 2018-03-26T21:04:04.817
The puzzle is whether MAC addresses for USB-Eth adapters are stored in the registry, and if so, where.
The goal is to ensure that when Win10 starts IP addresses originally set as fixed IPs for each USB-Eth adapter (seven or eight of them) are as they should be every time, and if any were unplugged & replugged they're still right. Testing has shown that Windows isn't consistent, can assign the wrong IP to the adapter. Looking like info in the registry won't be useful though and just forcing assignments with a powershell script and netsh cmds might be the solution. – Andy-1 – 2018-03-27T18:41:43.590
1Are these static IPs set at the client level or the DHCP server level? Is there a reason you're defining them on the client and not the DHCP server? – music2myear – 2018-03-27T20:25:16.917
At the client level - they're set via the IPv4 Properties of the device in Windows. The PC is the host (controller) for several separate test setups so 192.168.1.1, 192.168.2.1, etc must consistently be the ports into the different test systems. Otherwise we talk to the wrong one. The nodes in the test also use fixed IPs, they don't have DHCP. – Andy-1 – 2018-03-28T13:31:02.697
Why is the device unplugged and replugged if it's a test system? Why not use netsh or similar to do your IP configuration and just name the interface accordingly? – Seth – 2018-06-20T13:28:47.963