Incorrect date & time on the cameras in offline mode
I have a C200 and C100 cameras which connect to 4G Tp-Link router. The router has restricted access and hence not all devices are given internet access. The cameras have restricted access and cannot access the internet. They work well, but the date and time are always wrong. I assume the cameras update time from an NTP server.
I'm hoping to get answers to the following questions to help me fix the issue.
1. Is it possible to make it update from the router's time settings?
2. Is it possible to fix this issue in offline mode?
3. Is there a list of NTP servers that the camera uses so I can enable those IPs on my router?
4. I tried opening up outgoing UDP port 123 (NTP port), but that also doesn't fix the issue. Which ports can I allow in the router for the cameras to access your NTP servers?
Do you suggest any other method so as to allow my cameras work without internet?