What is FQDN?
FQDN stands for Fully Qualified Domain Name. It’s complete domain name for a computer or host on the internet. FQDN is made of two things: hostname and domain name.
Let me give you an example for demonstration.
FQDN for my mail server is
The hostname is
The domain is
You will need:
- IP Address
Edit hosts file
/etc/hosts file and append this like this.
# vim /etc/hosts ... 192.168.1.100 myemailserver.abdullah.today myemailserver ... :wq!
Replace IP address with your host IP, hostname with what your want to set or what you already have set.
/etc/hostname and replace with your new hostname if you want to change
hostname as well.
# vim /etc/hostname myemailserver :wq!
Or you can use
hostnamectl to set hostname.