I have a Mikrotik 750GL with the NTP package installed. The router NTP client is happily syncing with an external NTP server and setting the router time. I have also enabled the router NTP server and want to use it for setting the time on some IP cameras I have on a separate VLAN.

 

So far so good. I can query the router NTP server from the IP camera (it runs a lite version of Linux) and get a response (after adding the appropriate firewall rule to allow 123 UDP traffic).

 

The problem is the camera ntpd daemon refuses to set the clock, even though it is getting what looks like a valid response.

 

If I open up 123 UDP to the internet and use a *proper* NTP server, the camera happily syncs the clock.

 

Is it possible the Mikrotik NTP server is sending a non-compliant response? Or could it be the fact it is not a *proper* NTP server and the camera NTP client requires one?

 

Not the end of the world, as I can allow external access for this one port (123 UDP), but the OCD in me wants this to work properly!