The Ports on Apache can be changed on two positions:
/sites-available/000-default.confports.confPer Default, both .conf Files dictates Apache to listen on Port 80.
I want to set Apache to listen on a specific port. It seems, that ports.conf overrides the values of 000-default.conf
Where is the correct place to change the Port when the Server runs only on one single IP-Adress?
Ports can be changed in ports.conf alone. The various site configs contain definitions of what to serve on the open ports. This means that if you define a VirtualHost like this:
<VirtualHost 0.0.0.0:1234>
but you don't have a corresponding Listen 1234 directive, then the VirtualHost definition above is a no-op.
So in order to make Apache listen on an other port, you need to include the Listen directive in ports.conf (technically any other file would do, but it is a good idea to write config snippets where they belong), and make a VirtualHost entry in one of the config files in sites-available. After this, use a2ensite to enable the created config.
