nfssec(5)nfssec(5)NAMEnfssec - overview of NFS security modes
The mount_nfs(1M) and share_nfs(1M) commands each provide a way to
specify the security mode to be used on an NFS filesystem through the
option. mode can be either or These security modes may also be added
to the automount maps. Note that mount_nfs(1M) and automount(1M) do
not support at this time.
The option on the share_nfs(1M) command line establishes the security
mode of NFS servers. If the NFS connection uses the NFS Version 3 pro‐
tocol, the NFS clients must query the server for the appropriate mode
to use. If the NFS connection uses the NFS Version 2 protocol, then
the NFS client uses the default security mode, which is currently NFS
clients may force the use of a specific security mode by specifying the
option on the command line. However, if the filesystem on the server
is not shared with that security mode, the client may be denied access.
If the NFS client wants to authenticate the NFS server using a particu‐
lar (stronger) security mode, the client wants to specify the security
mode to be used, even if the connection uses the NFS Version 3 proto‐
col. This guarantees that an attacker masquerading as the server does
not compromise the client.
The NFS security modes are described below. Of these, the modes use
the Kerberos V5 protocol for authenticating and protecting the shared
filesystems. Before these can be used, the system must be configured
to be part of a Kerberos realm.
Use authentication. The user's UNIX user-id and group-ids are
passed in the clear on the network, unauthenticated by the
NFS server . This is the simplest security method and
requires no additional administration. It is the default
used by HP-UX NFS Version 2 clients and HP-UX NFS servers.
Use a Diffie-Hellman public key system
which is referred to as in the forthcoming Internet RFC).
Use Kerberos V5 protocol to authenticate users before granting access
to the shared filesystem.
Use Kerberos V5 authentication with integrity checking (checksums) to
verify that the data has not been tampered with.
User Kerberos V5 authentication, integrity checksums, and privacy pro‐
(encryption) on the shared filesystem. This provides the
most secure filesystem sharing, as all traffic is encrypted.
It should be noted that performance might suffer on some sys‐
tems when using depending on the computational intensity of
the encryption algorithm and the amount of data being trans‐
Use null authentication
NFS clients using have no identity and are mapped to the
anonymous user by NFS servers. A client using a security
mode other than the one with which an HP-UX NFS server shares
the filesystem has its security mode mapped to In this case,
if the filesystem is shared with users from the client are
mapped to the anonymous user.
lists the NFS security services. Do not edit this file. It is not
intended to be user-configurable.
NFS security service configuration file
SEE ALSOautomount(1M), mount_nfs(1M), share_nfs(1M), rpc_clnt_auth(3N),