Nagios Installation CentOS 5.2

Change your repository
http://tlepsh.blogspot.com/2009/03/yum-ftp-only-repository.html
Add dag repository to your configuration

[dag]
name=CentOS-5 - Plus
baseurl=ftp://ftp-stud.fht-esslingen.de/dag/redhat/el5/en/x86_64/dag/
enabled=0
gpgcheck=0

Install nagios
#yum --disablerepo=\* --enablerepo=dag,alteredbase install nagios

Start nagios
#/etc/init.d/nagios start

Restart web service
#/etc/init.d/httpd restart

Create a password for nagiosadmin user
#htpasswd -c /etc/nagios/htpasswd.users nagiosadmin

Install nagios plugins and perl module that you will need
#yum --disablerepo=\* --enablerepo=alteredbase,dag install nagios-plugins.x86_64
#yum --disablerepo=\* --enablerepo=alteredbase,dag install perl-DBI perl-DBD-ODBC,perl-Convert-BER.noarch