How to Set Up a Hostname via Command Line on Linux

1. Temporary Hostname Change (Resets on Reboot)

To temporarily change the hostname, use the hostname command. Note that this change will not persist after a reboot.

sudo hostname NEW_HOSTNAME

Replace NEW_HOSTNAME with your desired hostname.

2. Permanent Hostname Change

To make the hostname change persistent across reboots, follow these steps:

a. For Modern Linux Systems Using hostnamectl

Most modern Linux distributions use systemd. Use the following command:

sudo hostnamectl set-hostname NEW_HOSTNAME

This will update the hostname permanently.

b. For Older Linux Systems

1. Edit the /etc/hostname file:

   sudo nano /etc/hostname

   Replace the existing hostname with NEW_HOSTNAME and save the file.

2. Update the /etc/hosts file:

   sudo nano /etc/hosts

   Find the line starting with 127.0.0.1 and ensure it maps to the new hostname:

   127.0.0.1   NEW_HOSTNAME

3. Apply the changes:

   sudo systemctl restart systemd-hostnamed

   Alternatively, reboot your system:

   sudo reboot

3. Verify the Hostname

After making the changes, you can verify the hostname using one of the following commands:

hostname

Or:

hostnamectl

Both commands will display the current hostname.