:;8766 TCP/UDP: Required for general Steam communication.
:;27016-27030 UDP: Required for Steam queries. This allows the server browsers to see your server through Steam.
:;3724 TCP: The Wurm Unlimited server communicates with clients on this port. (This port may be modified, see [[Server_administration_(Wurm_Unlimited)#Local_Server|Local Server Configuration]]):;7220, 7221 TCP: These are ports used for RMI and intra-server communication. (These ports may be modified, see [[Server_administration_(Wurm_Unlimited)#Local_Server|Local Server Configuration]])
'''Note''': Your server will start without the Steam ports opened, but it will only be visible on the ''LAN'' tab of the server browser, and only to local clients.