We generally see the term FQDN or
Fully Qualified Domain Name and generally though that is is like a secret magic which provides some information about the servers and hosts. No. The answer is no the FQDN provides no secret or magic. We use FQDN in order to specify host names in a hierarchical manner. Below we will look how we calculate FQDN
Host name is used to identify hosts with meaning full names. For example when we setup Windows operating system the Windows set the hostname of the computer with the created user name like
IsmailPC . Of course we can change this host name what ever we want. Following list provides example host names.
Production1 LabPC Poftut2 Home www
Domain name is use to create a domain with a name. Internet provides a consistent and unique domain name hierarchy. For example
poftut.com specifies this site which is a domain name. We can use domain names not just sites also other things like databases, services etc.
FQDN = Host Name + Domain Name
Now we came to the real topic. We have learned the basics which creates FQDN. Fully qualified means the whole and domain name cames after that. Fully qualified domain name consist of
Host name + Domain name . FQDN specifies the host whit out any extra description. For example:
www.poftut.com specifies the host which provides
www or web services.
Automatic WWW Host name
Normally while surfing internet we can type URL as
poftut.com . This is not a fully qualified domain name even do not provides the host name. But the browser automatically add
www as default as it expect from us to surf in
poftut.com web site.
Partially Qualified Domain Name
Host names can be named as Partially Qualified Domain Names. Because host names do not provides the domain name. We can only use host name if we know or automatically add the domain name to the host name. For example if we are in the same domain we can use PQDN for communication and specification.