Network Information Service (NIS) B.11.31.04 Administrator's Guide

Shadow password mode enhances the password security of the system by
maintaining user passwords in a different file called /etc/shadow, and replaces
the encrypted password in the passwd file with x. This enhances the password
security of the system. You can convert a system to shadow mode using the pwconv
command , and revert the system using the pwunconv command. Shadow
password mode enables the NIS subsystem to recognize a system in shadow mode
and to build, store, and retrieve the password information accordingly. For more
information, see pwconv(1M) and pwunconv (1M).
NOTE: When a system is in the shadow password mode, the encrypted password
information used for creating NIS password maps is present in the /etc/shadow
file and is visible in the passwd maps (passwd.byname and passwd.byuid).
To enable this feature, a variable, SHADOW_MODE, is introduced in the /etc/
rc.config.d/namesvrs file. By default, the value of the SHADOW_MODE variable
is zero. To enable the shadow password mode, you must set this variable to one:
SHADOW_MODE=1.
In order to build the NIS maps to interpret the passwd and shadow files, the
SWFILE option in the /var/yp/makefile file must reference the shadow
password file:
# ypmake SWFILE=<shadow_file_name>
The default value for the SWFILE option is /etc/shadow. For more information
about the SWFILE option, see ypmake (1M).
• Multi-Homed Node
A multi-homed node is a node that has multiple network interfaces configured.
Multi-homed nodes enable an NIS client to obtain the closest address of the host
when it looks for a specific host name. The NIS server can index hosts with multiple
entries in the hosts and ipnodes database. While building the NIS maps, the ypmake
option identifies multiple entries with the same hostname, and accommodates the
entries in the maps with the aid of the multi and multi.awk scripts.
In previous versions of HP-UX, only the first address listed for a host was built
into the NIS maps. If a host has multiple entries in the database and the ipnodes
map is queried, all the entries are returned. If the hosts map is queried, then the
address nearest to the NIS client is returned.
• Support for IPv6 Protocol
NIS clients and servers support the IPv6 protocol.
The maps that store host information for NIS are hosts and ipnodes. The /etc/
hosts file contains both IPv4 and IPv6 information. When NIS maps are built,
NIS picks the IPv4 information from the /etc/hosts file to build the hosts maps
that contain only IPv4 information. It also selects the /etc/hosts file to build
the ipnodes maps, such as ipnodes.byaddr and ipnodes.byname, that contain both IPv4
20 Introduction