Unknown device connecting via ethernet?

I posted this is security but I'm thinking it might be more valuable in here.

I've noticed an unknown device connecting to my network at around 2:55am to just gone 3am each morning. I've only just noticed this when I was looking through the home network page.

It's listed as a proper device and is issued an IP address by the router.

As anyone else had or noticed anything like this happening?

The only logical thing I can think of is that maybe because I've got 2 switches networked together maybe its detecting the second switch or something? It's odd though.

I checked the log as far back as it will go and it's doing the same thing each morning.

Anyone have any ideas?

Yes, what device does the MAC say it is? Printer? TV? Fridge?

These are the log lines that appeared last night.

03:03:52, 22 Nov. (5970622.730000) Device disconnected: Hostname: Unknown-04-a1-51-6a-2e-39 IP: 192.168.1.69 MAC: 04:a1:51:6a:2e:39

02:58:59, 22 Nov. (5970329.270000) Lease for IP 192.168.1.69 renewed by host Unknown-04-a1-51-6a-2e-39 (MAC 04:a1:51:6a:2e:39). Lease duration: 1440 min

02:58:59, 22 Nov. (5970329.270000) Device connected: Hostname: Unknown-04-a1-51-6a-2e-39 IP: 192.168.1.69 MAC: 04:a1:51:6a:2e:39 Lease time: 1440 min. Link rate: 1000.0 Mbps

02:58:59, 22 Nov. (5970329.210000) Lease requested

I've not connected anything new to the network. Wireless is turned off. I have 5 devices on the network, all via ethernet, yet on the table its now showing 6 with that Unknown device included.

If it had just been a one off entry then I'd consider it a glitch somewhere. But it seems to be connecting at a similar time every night for at least the past week (maybe longer).

I have 1 laptop connected via ethernet during the night. It's listed with its own mac/ip address. So its not that device.

It seems very odd.

Yeah, it's a Netgear device

This is interesting.. I was looking up things over the internet about this issue and in one post there is a site called: http://www.macvendorlookup.com

I typed in the mac code in there and its listed as belonging to netgear. So the only netgear devices I have on the network are the 2 netgear switches. So it must be one of them.

Edit: Think we posted at the same time.. Thank you for your help.

Edited by bowdon (Sat 22-Nov-14 12:30:40)

It sounds as though it's a smart switch checking for firmware updates.

Netgear powerline adaptors? If you have a smart TV, they tend to check for updates in the middle of the night. Mine is via a powerline adaptor, which only 'wakes up' when the TV is active.

Not in the OP's case unless he has some he's forgotten.