NAME
nfs_portmon — enable/disable the NFS server's source port verification check
VALUES
Allowed values
Minimum: 0 - disable checking
Maximum: 1 - enable checking
DESCRIPTION
nfs_portmon
controls some security checking that the NFS server can do
in an attempt to enforce integrity on the part of its clients. The NFS server
can check to see whether the source port from which a request was sent is
a reserved port; a reserved port is a port whose port number is less then
1024. For BSD-based systems, these ports are reserved for processes being run
by privileged users. This checking helps prevent users from writing their
own RPC-based applications which defeat the access checking that the
NFS server uses.
Who Is Expected to Change This Tunable?
The distributed file system administrator should examine the value of
this parameter if he or she wishes to prevent malicious users from
gaining access to files by using an NFS server they
would not ordinarily be able to access.
Restrictions on Changing
The
nfs_portmon
tunable is dynamic; any change will take effect immediately on the
running system.
The reserved port notion is not universally supported. Therefore,
interoperability problems might result if this checking is enabled.
What Are the Side Effects of Enabling This Check?
Some NFS clients may not be able to connect to the NFS server.
WARNINGS
All HP-UX kernel tunable parameters are release specific.
This parameter may be removed or have its meaning changed in
future releases of HP-UX.
Installation of optional kernel software, from HP or other vendors,
may cause changes to tunable parameter values. After installation,
some tunable parameters may no longer be at the default or
recommended values. For information about the effects of
installation on tunable values, consult the documentation
for the kernel software being installed.
For information about optional kernel software that was
factory installed on your system, see
HP-UX Release Notes
at
http://docs.hp.com.
AUTHOR
nfs_portmon
was developed by Sun Microsystems, Inc.
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