How to setup domain name in Linux server

Learn how to setup domain name in RedHat, Ubuntu, CentOS, Fedora like Linux servers. Also see how to verify domain name in Linux and FQDN setup in Linux

Many companies have internal domain for their IT infrastructure. This needs their servers to be configured with domain name. This will ensure all servers will have FQDN (Fully Qualified Domain Name). For example server12 is hostname and server12.kerneltalks.com is its FQDN. In such setup, many tools, monitoring requires server’s to be identified by FQDN only.

For such scenario you have to configure domain name for your Linux server. We will walk you through steps needs to be taken to setup domain name on your Linux server.

First of all, check if your server is having domain name already set up or not using below command :

If you get output like above then your server is configured with domain name. If your output is blank then you have to setup domain name for your server.

Without further delay lets jump into steps to configure domain name.

Step 1.

How to setup FQDN in Linux?

First thing to be done is add FQDN to your hostname in /etc/hosts file.

To confirm your FQDN, run below command :

Output should be hostname.domain name

Step 2.

Configure domain name in Red Hat RHEL, Fedora and CentOS

Add below line in /etc/sysconfig/network

DOMAINNAME=<domainname>

Add below parameter in /etc/sysctl.conf

kernel.domainname = <domainname>

Configure domain name in Ubuntu

Edit your hostname (not FQDN) in /etc/hostname file. and restart hostname service. If you see below error :

you can set hostname using :

Once done, confirm normal hostname (using hostname) and FQDN (using hostname -f)

Step 3.

Add domain in /etc/resolv.conf. This file used for setting nameservers as well.

This addition make sure that you can resolves hostnames within your domain.

Step 4.

Confirm that changes are working perfectly. Question is how to check domain name of Linux server?

Below are the commands to check hostname, FQDN and domain name of your server.

hostname command shows your server’s hostname. hostname -f shows your FQDN. dnsdomainname command shows your domain name of server!