:;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]])
The following ports should be allowed by your firewall only if you are using multiple servers. Even then, you should ensure that your network security only allows traffic from known sources to these ports:
:;7220, 7221 TCP: These are ports used for RMI and intra-server communication. These must be open on the local machine but should NOT be publicly available. They bind to the Local IP address. (These ports may be modified, see [[Server_administration_(Wurm_Unlimited)#Local_Server|Local Server Configuration]])