Hikvision Cameras and Surveillance Station NTP

I've got the camera's running on Survilence Station. This was pretty much plug and play and was picked up by SS just fine.

Problem occurs with NTP the cameras dont like to talk to SS. "Failed a connection to Test Server". In the server address field i've put in the IP of the NAS (whch is hosting Survilence Station)

Noticed that the cameras dont have the correct default gateway so corrected that to reflect the router IP address yet still fails NTP.

Yet it does work when you point them to...

Hikvision Cameras and Surveillance Station NTP