I am sorry, but maybe I'm too stupid to get it running....
In the meantime I have familiarized with zypper and got it working by setting up a new repository and a proxy. The tool/process is much smarter than a tarball installation.
However after installing php5 I still got the same error messages. (403 error) At least for one time it was asked for my nagios account but again the start page wasn't shown properly.
My nagios.conf hasn't been changed and nearly looks like above example.
I am unsure which procedure to follow, I was looking at http://php.net/manual/en/install.unix.apache2.php
I am wondering at step 7 if something is wrong since I don't have libphp5.so file ? Is this a recommended procedure ?
in the Nagios Webfolder Nagios/share I can see a index.php file, shouldn't there be a index.html file as well, as I can see in my other running nagios instance ?
Maybe it makes sense to uninstall everything and start from the beginning ? I am not experienced with linux hence unsure if it would make any sense.
Thanks for any comments.