How to set hostname and FQDN on CentOS 7 and RHEL 7

The tutorial will explain about how to set hostname and FQDN on CentOS 7 and RHEL 7 (Red Hat Enterprise Linux 7). In our previous post “How to change hostname on CentOS and Red Hat“, we have already define the difference between hostname and FQDN. Hence suggest to read this post.

In Red Hat Enterprise Linux 7 or CentOS 7 , we have found slight changes.

You must have the ip address of system , which you can get by using the command ip addr list.

The given below is our system information, replace these values as per your system information.

IP Address : 192.168.56.101
Hostname : nix (We have selected this hostname, use hostname as per your interest)
FQDN (Fully Qualified Domain Name) : FQDN is combination of hostname+domain-name . Hence , here we are taking domain name as example.com .Therefore FQDN is nix.example.com

To change the hostname and FQDN on RHEL 7 and CentOS follow the given below steps.

Step 1: Edit /etc/hosts file

Now edit the /etc/hosts file in system. And add new line as given below

vi /etc/hosts

192.168.56.101 nix.example.com nix

This is the screenshot from our system.

Step 2: Edit /etc/hostname

Edit the /etc/hostname file and give the hostname you have selected.

vi /etc/hostname

nix

The below given is reference from our system.

[root@localhost ~]# cat /etc/hostname
nix
[root@localhost ~]#

Alternatively,you can also use hostnamectl command to set the hostname. It also update the /etc/hostname file which we have edit manually in above steps.

hostname nix is used in below given command.

hostnamectl --static set-hostname nix

Step 3: Print the hostname and FQDN

Now you do not require to restart or logout-login from RHEL 7 and CentOS 7 which is the best thing we have found. Hostname and FQDN are set.
Now print the hostname and FQDN of system.

To print the hostname ,use the command –

hostname

To print the FQDN ,use the command –

hostname -f

Whereas, in case hostname and FQDN is not taking effect. Then run the below command

systemctl restart systemd-hostnamed

Below given is reference from our system

[root@nix ~]# hostname
nix
[root@nix ~]# 
[root@nix ~]# hostname -f
nix.example.com
[root@nix ~]# 
[root@nix ~]#