I am working with Ethernet based devices, similarly to http://www.rfcode.com/rfid-reader-inventory-tracking-system-m250-fixed-reader. Unfortunately, type of the devices I am using, have been out of production for number of years, and manufacture does not sell or support them anymore.

At work, we have pair of those devices and they work fine and show up on software provided by manufacturer at two different IPs: and

So, I took one of the devices home with me and connected it to my PC through the Ethernet (direct connection, bypassing my home router). Tried various IPs, including the ones above and manufacture recommended IP.

My question: How can I find out IP address of the device that is connected to my PC through the Ethernet ? Running on Windows 7.

Clarification: At work, devices are plugged into into a network switch.

Edit(some additional information): At work, I connected the device, same way, I had it at home (PC was off company's network) Surprisingly, device with IP worked fine. Took the same device back home, it didn't work ! Later on today, I will try different PC.

  • 2
    Sorry, cant comment since I do not have sufficient reputation. Can you try connecting it with the router. Then in the router you should be able to see the device connected. Also are you using cross cable when connecting device directly with PC?
    – Hemang
    Aug 1, 2014 at 14:48
  • @Hemang, I will investigate on how to connect to my home router. Don't know if I have crossover cable or regular one, but it seems like it does not matter (see edit). I used the same cable, I used at work.
    – newprint
    Aug 1, 2014 at 17:03

3 Answers 3


I'm going to assume that "at work" they are connected to a network with DHCP, and the addresses you mentioned were assigned dynamically (or perhaps DHCP reservation).

If you connect the device directly to your PC, you will have to rely on APIPA addressing, which isn't very reliable or easy to work with.

Instead, connect the device to your home router. Your router will automatically assign it an address on the same subnet as your home PC. To find the address that your router has assigned it, log into your router, and look for the "client list" (sometimes referred to as a table, status, etc.) It will be a little different depending on your specific router, but here is an example of how to do this step-by-step with a Linksys router. Below is a picture of the client list from a TP-Link router.

enter image description here

Ideally it will be named something identifiable to you. If not, just try the address of each client until you get a connection.

  • I was able to connect to the device, and through the router !! Thanks !
    – newprint
    Aug 3, 2014 at 0:58

I'm going to assume that "at work" they are also connected directly to a PC by ethernet. If so, and they had these addresses, it is a static address set in the device.

Edit: The question has been revised and it now appears the device is not using a static address. I'm leaving this answer here since it will help others who do need to interface with ethernet devices with a static address.

On your home PC, you would need to set a static address in the same subnet. Open Control Panel > Network and Internet > View network status and tasks > Local Area Conenction > Properties > Internet Protocol Version 4 > Properties. Select Use the following IP address and enter an IP address such as (the last number can be anything not in use) and a subnet mask of You can leave the other fields blank. You can now access the device using the same address you used at work.

Make sure to record these instructions so you can undo the changes after you're done with the device.

  • I should have noted that at work, devices are plugged into a network switch. I will try your method.
    – newprint
    Aug 1, 2014 at 16:09
  • @newprint Is the switch connected to anything that might be providing DHCP service, such as a router, gateway, modem, or server?
    – Jason
    Aug 1, 2014 at 16:11
  • to be completely honest, I don't know (colleague who is responsible for our network, is on vacation). Though, I went to command prompt as it was advices by @Manfred Radlwimmer, and found out that type is dynamic
    – newprint
    Aug 1, 2014 at 16:19
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    @newprint Ok, that changes everything. Ignore this answer then. I will followup with another answer.
    – Jason
    Aug 1, 2014 at 16:29

easies way would by to check your arp table

Windows 7 has the arp command, so you could list all devices known per interface by typing this into your console (cmd)

arp -a

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