You should open port 443 for the HTTPS communication and port 80 for HTTP communication (optional).
Please also make sure the websocket and UDP (for the local time synchronization) communications are working on the network properly.
Ports and tools used:
|Nginx||80, 443/TCP – inbound|
|OpenSSH||22/TCP – inbound|
|Docker daemon||2376/TCP – inbound (enough to restrict to our Management server’s IP).This is optional, if security is a concern, we can manage containers locally.|
|Chrony||123/UDP. This is optional, it needs if you want to use content synchronization (instead of local UDP local time synchronization).|