IETF RFC 7530 PDF

The Network File System (NFS) version 4 protocol is a distributed file system protocol that builds on the heritage of 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.

This document, together with the companion External Data Representation (XDR) description document, RFC 7531, obsoletes RFC 3530 as the definition of the NFS version 4 protocol.