RumbleMouse

I recently bought a home in New Mexico that has 7 pretty nice PTZ security cameras. Unfortunately the sellers took the server with them when they moved. What I have is 7 AXIS Q61xx (I think) cameras connected to PoE devices. All the cameras are powered up and track you as you walk across their view. The cameras show up on my local network router but my attempts to log in to them directly have failed. I don't have the IP login credentials. I'm in the process of moving and when I get back to the house next week I will attempt to do factory resets on the cameras. So I will need some sort of video management software for viewing and recording. Anybody make some recommendations? I don't need anything too elaborate and would appreciate something that is fairly quick and simple to get up and running. I also don't want to miss out on any useful functionality by choosing the wrong software and having to start over. And hardware. My initial thought is to run this on a little NUC desktop PC. Is there any significant advantage to using a dedicated security recording device? Again, asking for recommendations.

There's no risk of the previous owner having access. There is new broadband service with new cable modem and new routers. I wasn't aware there might be an SD card in the cameras. I'll have to check into that.