Cannot connect to cameras DS-7608NI-K2/8P

Hi, we have a DS-7608NI-K2/8P connected to 4 Colorvu cameras, I would like to turn the LED lights off on the cameras at night but cannot login to them, I have ticked Enable Virtual Host under Network > Advanced > Other, then go to Camera Managmant and in the join section click the link and just get Cannot reach this page, the plugin is installed and working as live view works fine, any ideas?
Thanks all