Another device on your network is using your computer's ip address

Has anyone seen this error message before, "Another device on your network is using your computer’s ip address. The connecting device does not have a static ip address assigned to it. And every time the Peplink router tries to assign a different/new IP address the error message pops right up. We have been using this router (Peplink Balance One) at the location for almost 3 years. The configuration has not change.

Can someone help me?

Is it possible there is a second DHCP server on the network? Did a wireless access point get added with DHCP enabled?

We are not aware of any devices with a DHCP server on the network (all of our APs are in bridge mode). We will take a look tomorrow to make sure no one has connected anything directly to the router.

Are there other possible causes that would result in the router attempting to give out duplicate IP addresses?

Thanks for your help!

Does an ARP command from your PC show the IP address of the Balance with the proper MAC address?

We have not been able to do the ARP test yet. We did confirm there were no other devices connected to the router other than our wireless access points.

Sometimes after a reboot and the client computer’s reboot we are able to get a particular client

connected and I was able to give him a DHCP reservation (screen shot attached). Even after the DHCP reservation, he continues to get that error message (screen shot attached) and his computer bounces between active and inactive on the Client List screen.

IP conflicting can caused by the client connected to the WIFI AP. I would suggest the following:

  1. Reserved other IP address the device that having issue, monitor the status.
  2. Check the WIFI AP for the client connected list and verify the IP used.
  3. Perform packet capture from Balance AP & WIFI AP and check on the traffics generated by the clients.

We have fixed the issue by replacing a WiFi AP that was connected directly to the router and was a wireless bridge to the rest of our network. Here is what we found -

When the “affected” AP was unplugged from the router, everything worked properly. Within seconds of being plugged into the router from a power off state (before sufficient time to boot up), the AP would cause the router to either stop giving out DHCP addresses or cause the error of address already in use. It was preventing most internet traffic except for a random assortment of wireless clients that would sporadically and randomly be able to access the internet. As soon as this AP was replaced, everything worked properly again. It would even cause the error to appear on a client computer that had been assigned a static IP address outside the DHCP network.

Thank you for your help looking into the issue, much appreciated.