domainname – Display and Set the System’s NIS Domain Name

The domainname command is used to display or set the system’s NIS (Network Information Service) domain name. NIS is a client-server directory service protocol used to distribute system configuration files, such as user and group information, across a network. The domain name is used to identify the NIS domain to which the system belongs.


To display the current NIS domain name, simply run the command domainname without any arguments:

$ domainname

This will output the current domain name, which in this example is

To set a new NIS domain name, use the domainname command followed by the desired domain name:

$ domainname

This will set the new domain name to


The domainname command has the following options:

Option Description
-f, --fqdn Display the fully qualified domain name
-y, --yp Display the NIS domain name
-h, --help Display help information and exit
-V, --version Display version information and exit

Troubleshooting Tips

If you are unable to set the NIS domain name, you may need to check that the NIS service is running and that the system is configured to use it. You can check the status of the NIS service with the following command:

$ systemctl status ypbind.service

If the service is not running, you can start it with the following command:

$ systemctl start ypbind.service


  • The domain name is stored in the /etc/defaultdomain file.
  • The domainname command is not used to set the DNS domain name, which is set using the hostname command.