It is used to configure where the C library looks for system information such as host names and user passwords.
B.
It is used to configure network protocol port numbers such as for HTTP or SMTP.
C.
It is used to configure LDAP authentication services for the local system.
D.
It is used to configure which network services will be turned on during the next system boot.
The Answer Is:
A
This question includes an explanation.
Explanation:
The nsswitch.conf file is a configuration file that determines the sources and the order of the sources that are queried for various system databases, such as user information, group information, host names, network services, and more. The C library uses this file to look up various system information when a program or a command requests it. For example, when a user logs in, the C library will use the nsswitch.conf file to determine where to find the user’s password, whether it is in the local /etc/passwd file, or in a remote LDAP server, or both. The nsswitch.conf file allows the system administrator to configure the system databases in a flexible and modular way. References:
[LPI Linux Essentials - Topic 106: The Linux Operating System]