File sharing with Network File System (NFS) is the traditional way on Unix and Linux for remote hosts to be able to mount filesystems over a network and interact with them as if they were mounted locally. Although RHEL 7 supports both NFSv3 and NFSv4, there is no longer any support for NFSv2. The RHEL 7 client will default to NFSv4 and falls back to NFSv3 if a connection cannot be established. Using NFSv4 simplifies location of services behind a firewall with only the TCP port 2049 required for client access; however, we will demonstrate both the NFSv4 and v3 firewall configurations. During this chapter, the following topics will be covered: