domainname

Display or set the system's NIS/YP domain name

TLDR

Show current NIS domain name

$ domainname

Set NIS domain name

$ sudo domainname [example.com]

Set NIS domain name from a file

$ sudo domainname -F [/etc/nisdomain]

Clear domain name

$ sudo domainname ""

domainname displays or sets the system's NIS (Network Information Service) domain name. This is different from the DNS domain name and is used for NIS/YP services.Without arguments, it shows the current NIS domain. With an argument, it sets the domain name (requires root privileges). The setting is typically not persistent across reboots without additional configuration.

PARAMETERS

-v, --verbose

Be verbose about actions.

-F file, --file file

Read domain name from the specified file.

-y, --yp, --nis

Display the NIS domain name (default behavior when invoked as domainname).

-h, --help

Display help and exit.

-V, --version

Show version information and exit.

INSTALL

sudo apt install hostname

sudo dnf install hostname

sudo pacman -S net-tools

sudo apk add net-tools

sudo zypper install hostname

brew install net-tools

nix profile install nixpkgs#hostname

CAVEATS

Do not confuse this with the DNS domain name; use dnsdomainname for that. Setting is not persistent by default across reboots. NIS is deprecated in favor of LDAP and Kerberos. Rarely used on modern systems.

HISTORY

domainname dates back to the early days of NIS (originally Yellow Pages, YP), developed at Sun Microsystems in the 1980s. NIS provided centralized authentication and configuration for Unix networks. While largely replaced by LDAP and Kerberos, the command remains for compatibility.