caprover/docs/firewall.md

id, title, sidebar_label

id	title	sidebar_label
firewall	Firewall & Port Forwarding	Firewall & Port Forwarding

Captain uses:

• 80 TCP for regular HTTP connections
• 443 TCP for secure HTTPS connections
• 3000 TCP for initial Captain Installation (can be blocked once Captain is attached to a domain)
• 7946 TCP/UDP for Container Network Discovery
• 4789 TCP/UDP for Container Overlay Network
• 2377 TCP/UDP for Docker swarm API
• 996 TCP for secure HTTPS connections specific to Docker Registry

Or simply disable firewall entirely. In case of an ubuntu server, run ufw disable.

Also, if you are using Port Mapping to allow external connections, for example from your laptop to a MySQL instance on Captain, you will have to add the corresponding port to the exclusion as well.