Problems Solved

PROBLEM OF THE FORTNIGHT

What’s this device on my network?

Q Periodically, I check if anyone is on my network apart from my own devices, using a program from NirSoft. Recently, I came across a device with the IP address 192.168.1.214. I recognise the first three parts of this, but I cannot find any device with 214. It apparently also has the code CA-5F-AD-85-FC-D9. This looks like a software serial number but on a search all I get is it might be a security certificate. Any ideas?

Martin Fletcher

A You didn’t tell us which NirSoft program you used, but we think it’s Wireless Network Watcher (www.snipca.com/39645), as this shows all sorts of information about devices connected to your router – including both IP and MAC addresses.

IP addresses are those that begin with 192.168.1, and which you recognise. MAC is short for ‘media access control’, which describes a unique string of hexadecimal numbers assigned by manufacturers of networking devices. We mention this because the code you cite (CA-5F-AD-85-FC-D9) is a valid MAC address. You can look these up online, using a tool like macaddress.io https://macaddress.io/, see screenshot 1) to find out who manufactured it. However, this one turns up a blank.

That’s not necessarily suspicious, as some products can be manufactured on a ‘white label’ basis, where the original maker sells on the product to a third-party vendor. But this fact doesn’t help us – or you – identify the mystery device.

Now, we should offer some reassurance by saying that this is most likely some gadget that’s easy to overlook or forget, like an old smart TV or digital photo frame, say. That