When an NFS URL is used, the connection will be made using TCP transport, NFS version 3, port number 2049, and a public file handle. If any of these requirements cannot be met, the client uses a secondary option.
The WebNFS client connects to the server, following these rules:
Use TCP protocol first. If the connection is refused, use UDP.
Use NFS version 3. If rejected, use NFS version 2.
Use port number 2049 on the server.
Use a public file handle as an initial file handle with a lookup request. If the request is rejected, use the Mount protocol.
If the public file handle is used, locking/sharing will be disabled.