The Name Service Switch determines where your system looks for host information to resolve a host name to an IP address.
For all types of information except host information, you can configure your system to use NIS (one of the NFS Services) or the local /etc file, in any order. HP recommends not to configure your system to use NIS.
For host information, you can configure your system to use BIND (DNS), NIS, or the /etc/hosts file. As mentioned earlier, HP recommends not to configure your system to use both NIS.
See HP-UX Internet Services Administrator’s Guide at the URL http://www.docs.hp.com/ hpux/netcom/index.html#Internet%20Services for more information on the Name Service Switch.