The mount protocol is separate from, but related to, the NFS protocol. It provides operating system-specific services to get NFS off the ground - looking up server pathnames, validating user identity, and checking access permissions. Clients use the mount protocol to get the first file handle, which allows them entry into a remote file system.
The protocol definition implies stateful servers because the server maintains a list of client's mount requests. This corresponds to current implementations which hold the mount list on stable storage. However, the mount list information is not critical for the correct functioning of either the client or the server. It is intended for advisory use only; for example, to warn possible clients when a server is going down. The server must provide a mechanism to eliminate redundant information from the mount list.