Why does apache throw the error "Could not reliably determine the server's fully qualified domain name, using 127.0.0.1 for ServerName"?

Issue

• When starting httpd, following message is displayed:

`httpd`: "Could not reliably determine the server’s fully qualified domain name, using 127.0.1.1 for ServerName"

• The Apache httpd configtest shows the following error message and httpd fails to start

RHEL 6

# service httpd configtest
httpd: Could not reliably determine the server's fully qualified domain name, using test.example.com for ServerName
Syntax OK

RHEL 7 onwards

# apachectl configtest
httpd: Could not reliably determine the server's fully qualified domain name, using test.example.com for ServerName
Syntax OK