Small campus type network (a half dozen buildings or so). I have network panels throughout, within what was supposed to be a range reserved for us (172.28.10.x). Friday, the client turned on a video conferencing unit that was programmed with the same IP as one of my panels. So, my server lost comm with that panel. After we tracked down the device with the duplicate IP and changed it, the network can no longer see my panel (with the same IP). I try pinging, and two different IP's reply. I changed my panel for a new one with a different IP, and was able to communicate with it over the same wire/port/switch the previous panel was using. And, as soon as I changed the new unit to the previous IP, I lost comm with that one, too. I know changing the IP didn't fry the new board, so why is the network not able to tell where that IP address is located? I rebooted the panel a few times before replacing, even changed the port the panel was plugged into.