# Network monitoring

1. yum install nagios.
2. Start the httpd and nagios services.
4. Define the network to be monitored by editing Nagios' configuration files. You can place your configuration in /etc/nagios/conf.g/foo.cfg. For example, the following will define a host named smtp.example.com and also check that smtp.example.com is providing an SMTP service:
define host {
use			linux-server
host_name		smtp.example.com
}
define service {
use			generic-service
host_name		smtp.example.com
service_description	SMTP
check_command		check_smtp
}

5. Load http://localhost/nagios in a browser. (Note securing Nagios so that it can be accessed away from localhost is beyond the scope of these notes.)

Fedora packages plugins such as check_smtp separately from the core Nagios package installed above. The following packages provide common plugins:

Plugin packageUse
nagios-plugins-pingCheck the availability of a host using ICMP
nagios-plugins-tcpCheck the availability of common Internet services including FTP and IMAP
nagios-plugins-httpCheck the availability of a HTTP/HTTPS service
nagios-plugins-smtpCheck the availability of a SMTP service
nagios-plugins-dnsCheck the availability of a DNS service
##### W. Michael Petullo

My research interests include free and open source software, system security, and network security.