Ok, it happens again. I've walked around the building and i can't seem to locate anything out of the ordinary (no conceptronic devices).
What the easiest way to get the mac adres from that device? Only thing i know now is that it is a conceptronic device and has the 192.168.0.1 ip-adres (which is outside my subnet).
Can't access the admin page of the device most of the time (sometimes it works but very slow).