Websites (web domains) and URLs

[dragosl]

Hello,

Sorry if this is a dumb question but I couldn't figure it out.

My example setup:

Server name: server1.example.domain

DNS zone : example.domain
Default ISPConfig zone records + A host1 + A ns + A server1

Website (web domain) with default settings: example.domain
Website (web domain) with default settings: host1.example.domain
No website defined for "server1.example.domain".

Question:

Given the above setup why does http://server1.example.domain point to host1.example.domain website?
How can I prevent this from happening?

What I want is that any URL such as http://server1.example.domain only to point to the corresponding website (web domain) IF created, otherwise just fail.

Thank you in advance.

Dragos