Hello everyone,
I just completed the Nagios installation, and I’m currently only monitoring the local host. I tried to add a new host from my network but I was unsuccessful… I tried generating a new hosts.cfg file and I did set up the redirection on the nagios.cfg to the host file, but every time I try to restart the nagios process it fails.
Any ideas ? Would truly appreciate it 
Had this post in the Nagios forums (but this is the right section)