You have a router, you want to know what it does all day long? Then MRTG is for you. It will monitor SNMP network devices and draw pretty pictures showing how much traffic has passed through each interface.
a high performance, extremely flexible system for monitoring trends in time-series data. Cricket was expressly developed to help network managers visualize and understand the traffic on their networks, but it can be used all kinds of other jobs, as well.
JFFNMS is a Network Management and Monitoring System designed to monitor a IP SNMP / Syslog / Tacacs+ Network. It can be used to monitor any standards compilant SNMP device, Server, Router, TCP port or anything you want, if you write a custom poller, we a
NagiosĀ® is an Open Source host, service and network monitoring program. Where can you get it? Right here. Can you get support for it? Yes! Get more answers to some of your basic questions about Nagios here.