Before you configure machines as NIS servers or clients, you must plan the NIS domain.
Decide which machines will be in your NIS domain. An NIS domain does not have to mirror your DNS domain. A DNS domain can have more than one NIS domain, and machines can exist in your DNS domain that are outside of your NIS domain.
An NIS domain name can be 256 characters long. A good practice is to limit domain names to no more than 32 characters. NIS domain names are case-sensitive. For convenience, you can choose to use your Internet domain name as the basis for your NIS domain name. Be aware that users might become confused if the NIS domain name includes capitals, but the DNS domain name does not. For example, if your Internet domain name is example.com, you can also name your NIS domain example.com. If you wanted to divide example .com into two NIS domains, for example, one for the sales department and the other for the manufacturing department, you could name one domain sales. example.com and the other domain manf. example.com.
Before a machine can use NIS services, the correct NIS domain name and machine name must be set. A machine's name is set by the hostname command. The machine's domain name is set by the domainname command. The hostname and domainname commands can be used to display the machine name and the NIS domain name.