[caption id=”” align=”alignnone” width=”400” caption=”Nagios “][/caption]

This past week I was able to try out some new software that I have heard about, Nagios. Nagios is an open source network monitoring tool. It can monitor servers/PC’s along with switches and routers. On the PC side there is a little light weight client that gets installed called NSClient++, which then Nagios then Monitors. Yeah, yeah, that’s all cool and good but what I really wanted to get working was the network monitoring with SNMP. At my work they have 3 switches and a Cisco Pix 501. I went through and allowed SNMP on the Cisco router and configure the Nagios file and It worked. Then I went through and did the other switches. When I found one of the GS724T switches was a Version 1 (older one) there was no SNMP option and after updating the firmware to the latest version I have kind of given up hope on that switch. The other switches on the other hand worked great. Here’s a pic of the basic Nagios service Next I really wanted to get the bandwidth usage working. So I needed to install MRTG on the ubuntu box. MRTG basically uses SNMP to get information from the devices every 5 minutes and logs it. Then it creates a web page with the data displayed in a graph. After that was working I then pointed the ports on the Nagios configuration to the log files from MRTG. Now the devices in Nagios show the ports up/active and bandwidth usage. detail screen.