System Administration Guide: Security Services

NFS Services and Secure RPC

NFS enables several hosts to share files over the network. Under the NFS service, a server holds the data and resources for several clients. The clients have access to the file systems that the server shares with the clients. Users who are logged in to the client machines can access the file systems by mounting them from the server. To the user on the client machine, it appears as if the files are local to the client. One of the most common uses of NFS is to allow systems to be installed in offices, while keeping all user files in a central location. Some features of the NFS service, such as the mount -nosuid option, can be used to prohibit the opening of devices, as well as file systems, by unauthorized users.

The NFS service uses Secure RPC to authenticate users who make requests over the network. This process is known as Secure NFS. The authentication mechanism, AUTH_DH, uses DES encryption with Diffie-Hellman authentication to ensure authorized access. The AUTH_DH mechanism has also been called AUTH_DES.