Question: My server is behind the firewall. What ports do I need to keep open?

Solution: If your server is behind the firewall, the following common ports need to remain open. 

Firewall Settings for HC Panel:
HC uses the following ports to communicate between primary and secondary machines, make sure it is allowed in the inbound and outbound firewall rules.

HC Administration Website: 8797 (Optional)
HC Provisioning Service: 8796
HC Portal API: 8798 (Only on Windows Master server)

HC Client Service 8795
HC Server Service 8794
Click & Apps Administration Website: 8799


Web Server:
HTTP 80
SSL 443
 FTP 21


Mail Server:
SMTP 25
SMTP SSL 465
IMAP 143
IMAP SSL 993
POP 110
POP SSL 995


Database Server:
MSSQL Server 1433
MYSQL 3306

DNS Server:
DNS 53

Remote Server Connection:
Remote Desktop Protocol (Terminal Service) 3389
 Linux SSH 22


Miscellaneous Ports:
LDAP 389
LDAP-S 636
NetBios 139
 RPC 593
   

External Reference: The Well Known Ports are assigned by the IANA. A good port assignment reference is available at http://www.iana.org/assignments/port-numbers