I recently needed to share some network utilization data with some non IT folks in our organization. I produced a quick report from a dynamic HTML page that contained multiple MRTG graphs. Needless to say the graphs did most of the talking while I just answered the questions. One person commented that they didn’t know we had purchased such an elaborate management and monitoring solution. In short we hadn’t purchased any high-end management or monitoring solution, but we had setup Multi Router Traffic Grapher (MRTG) and Round Robin Database (RRD) both of which were written by Tobi Oetiker with contributions from many others.
I’ve been personally using MRTG for well over 10 years now and I’ve yet to find any product (commercial or open source) that comes close. These two tools work hand in hand to help me graph and chart almost any SNMP value (you can also graph non-SNMP values but you need a script or something to collect the values) on almost any device connected to the network. The obvious examples for network engineers and architects such as myself is to use MRTG/RRD to help monitor current network utilization and forecast future growth. There are other examples such as graphing the temperature of a computer room or even the amount of rainfall. There are literally hundreds of examples but I’ll leave you to enjoy reading about them all from the MRTG web site.
Here are two quick examples;
In the above figures MRTG is graphing the average of ifInOctets and ifOutOctects over a 5 minute interval. As I said above you could graph almost any value you wished.
I also use MRTS by Thor Dreier to help get an idea of how much actually data is traversing a specific network or interface. When we recently installed an HP MAS (Medical Archive Solution) which was built around grid computing and virtual storage technologies we observed a 300% increase in WAN traffic as the MAS was replicating data for business continuity purposes.
I will admit that MRTG can be somewhat complicated for the fledgling network engineer. However, there are dozens of implementation guides now available on the MRTG web site, including support for running MRTG on Windows.