Default Configuration

A default nsswitch.conf file is supplied in the /usr/newconfig/etc directory. It contains the following lines:

hosts:     dns  nis  files
protocols: nis  files
services:  nis  files
networks:  nis  files
netgroup:  nis  files
rpc:       nis  files 

This is the default configuration. In other words, if you copy /usr/newconfig/etc/nsswitch.conf to /etc/nsswitch.conf, the Name Service Switch behaves the same way it would if no /etc/nsswitch.conf file existed.

If your /etc/nsswitch.conf file contains a syntactically correct line for a particlar type of information, that line is used instead of the default.

If you specify a name service for a particular type of information, but you do not specify four status=action pairs after the name service, the following default status=action pairs are used for any statuses you did not specify:

SUCCESS=return
NOTFOUND=return
UNAVAIL=continue
TRYAGAIN=return

So, for example, in the default configuration for protocols, NIS will be consulted first, and if NIS is not configured (the query returns UNAVAIL), the local /etc/protocols file will be consulted. If the query returns anything other than UNAVAIL, the /etc/protocols file will not be consulted.

Figure 5-1 “Default Behavior of the Name Service Switch” illustrates the default behavior of the Name Service Switch for host information lookups.

Figure 5-1 Default Behavior of the Name Service Switch