Network file system (NFS) is a network protocol that, in its most widely adopted forms, is defined in RFC 1094 for NFS version 2 and in RFC 1813 for version 3. By default, Server for NFS supports clients using either version. You can override this, however, and configure Server for NFS to allow access only by version 2 client computers. See To enable NFS v3 support for more information.
NFS relies on two transport protocols: Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). TCP is designed for high reliability, but at a greater performance cost.
Server for NFS supports both protocols. If server performance is more important to you than reliable data delivery, you can disable TCP support by Server for NFS. For more information about this, see To enable TCP support.