HP-UX Reference (11i v2 04/09) - 5 Miscellaneous Topics (vol 9)

nfs_portmon(5) nfs_portmon(5)

(Tunable Kernel Parameters)

NAME

nfs_portmon - restricts NFS services to clients from privileged ports

VALUES

Allowed Values

Minimum:

Maximum: 1

Default: 0

DESCRIPTION

The nfs_portmon tunable enhances security checking on the NFS server. When set to

1,itprevents

malicious users from gaining access to ﬁles exported by the NFS server. It checks whether the source

port from which a request was sent is a privileged port. The range of privileged ports is

512 to 1023.

Checking for privileged ports prevents users from writing their own RPC-based applications to defeat the

access checking used by the NFS client.

EXAMPLES

To set the variable, execute the following command on the target system:

kctune nfs_portmon=1

To unset the variable, execute the following command on the target system:

kctune nfs_portmon=0

WARNINGS

The privileged port notion is not universally supported. In addition, not all NFS client implementations

bind their transport endpoints to a port number in the reserved range. Therefore, interoperability prob-

lems may result if the tunable is set to 1.

AUTHOR

nfs_portmon was developed by Sun Microsystems.