nfs_portmon

Description

This parameter determines whether or not a client must use a ''privileged'' port for NFS requests. Only processes with superuser privilege may bind to a privileged port. The nfs_portmon parameter is binary. If it is set to 0, clients may use any available port. If it is set to 1, clients must use only privileged ports.

Value

Default: 0

Range: 0 or 1

When to Change

You should change this parameter only if it is absolutely necessary to maintain root privilege on your NFS mounted file systems and you have checked each NFS client to be sure that it requests a privileged port. If there are any clients requesting non-privileged ports, they will be unable to mount the file systems.

Additionally, changing the value of nfs_portmon to 1 can give a false sense of security. A process must have root privilege in order to bind to a privileged port, but a single ''insecure'' machine compromises the security of this privilege check.