Did you ever get, Error: You don’t have permission to access /nagios on this server while installing Nagios. We got this error also and we solved it too.
The chance when we got to deploy Nagios server in our network we struck with first error after installation of Nagios in Fedora 11 “Leonidas”. We followed the every steps, described in Nagios Quick Start Method.
Here is the URL of Quick Start… https://support.nagios.com/kb/article.php?id=96#Fedora
After completing the given procedure as it is. We faced this problem.
We were trying to use username nagiosadmin and the password which we set by htpasswd command(see the above quick start link).It was not login and giving the error….
You don’t have permission to access /nagios on this server “
To solve this problem, we installed the php package.
sudo yum install php
And problem get resolved,Now we can login with username nagiosadmin with the password.