real simple question ....

[expatCM]

I want to understand this but I got lost on a fundamental ... I am following the The Perfect Setup - Ubuntu Feisty Fawn (Ubuntu 7.04) Server.

In the tutorial the system is called server1.example.com and the hostname is server1.

Why? Why is the hostname not the same as the system name?

I only get a dynamic IP and so my domain is hosted externally. Does the server need to relate to an existing registered domain name on an external host to be included in the setup information?

The Postfix mail name also seems to refer to server1.example.com, is this just to give the server a unique identity or is it to relate to an external domain.

Ok ... I appreciate that is must be a real basic question but if anyone could explain it would be great

[falko]

Normally, when you have a static IP address, you use the hostname that belongs to this IP address as the server's hostname. Of course, you can also use your own hostname, but then you should create a DNS record for it.

If you have a dynamic IP address, it's better to use your own hostname. You could use a hostname from dyndns.org for this, for example.