IETF RFC 7531 PDF

The Network File System (NFS) version 4 protocol is a distributed file system protocol that owes its heritage to NFS protocol version 2 (RFC 1094) and version 3 (RFC 1813). Unlike earlier versions, the NFS version 4 protocol supports traditional file access while integrating support for file locking and the MOUNT protocol. In addition, support for strong security (and its negotiation), COMPOUND operations, client caching, and internationalization has been added. Of course, attention has been applied to making NFS version 4 operate well in an Internet environment.

RFC 7530 formally obsoletes RFC 3530. This document, together with RFC 7530, replaces RFC 3530 as the definition of the NFS version 4 protocol.