I am setting up a device (BNC RTSA spectrum analyzer) which connects to my Windows 7 laptop directly through the ethernet.

I can ping the device in the command window, but it does not show up when I run ipconfig.

I can use the developer's (BNC) GUI to find the device, but I have to manually enter the IP addresss. I can manually enter the ip address in my internet browser and connect to the device. (This proves the device is working and plugged in).

The device is configured to use DHCP. But if DHCP fails, the device creates an Auto-IP: 169.254.x.y.

I would like to avoid setting a static ip address, since I disconnect/connect my device to different computers. I would like my device to be discoverable.

Can I configure my Windows 7 machine network to find the device?

  • DHCP shouldn't be failing. Do you have a use case where you don't have a DHCP server? In that case, you might consider letting your Windows 7 box be the DHCP server. You could even use a dedicated network interface (perhaps a cheap USB adapter) to connect to the device. – Brad May 18 '16 at 1:57
  • Hi @Brad, thank you for your help. I don't think I understand your question about use case? I have been puzzled why the DHCP fails, I don't know where the failure originates and I don't know how to test this. I think you are pointing me in the right direction. – oogieoogieful May 18 '16 at 2:20

The device is not a network adapter, so it's never going to show up in ipconfig. I'm not sure what gave you that idea.

Ethernet devices are not "discoverable" like USB devices, unless you've got something like WINS or Bonjour running alongside. Consider two approaches:

  1. Use the static IP address. This is quick and dirty but a pain if you're on more than one network with different subnets.
  2. Configure your router such that when it sees the MAC address of your device during a DHCP query, it assigns the same address to it all the time. This way, you don't have to tamper with static vs. DHCP on the device.
  • Thank you for responding @codenoire. Yes, I was confused about ipconfig. I am not using a router (unless it's inside the laptop). There is an ethernet port on the device and my laptop: I connect the 2 with an ethernet cable. I suspect I have to change the setting of my LAN, network adapter, ethernet but I am not sure how. I could be totally misunderstanding how LAN, DHCP, TCP/IP, etc. work. – oogieoogieful May 18 '16 at 2:01
  • No router? Then you are connecting the devices with a crossover cable, or at least one device has a crossover mode. Non server versions of Windows do not have a DHCP server installed. The ethernet port on your laptop is being assigned an address by what is known as apipa. support.microsoft.com/en-us/kb/220874 – Xavier J May 18 '16 at 2:33
  • APIPA assigns randomly each time, and the only way to get around this would be to use the router as directed above, or to assign, or to assign two unique static addresses on both the device and your laptop, respectively. – Xavier J May 18 '16 at 2:37
  • I was under the impression that the network being public and unidentified was blocking me from accessing my device. I appreciate your help @codenoire, I don't need to avoid apipa necessarily, I think I can write a script to handle apipa on my network since Both my ethernet adapter and device generates their own apipa addresses. My orignal question probably does not make sense. I was incorreclty diagnosing a problem. – oogieoogieful May 18 '16 at 12:33

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