Savvy network managers have long known the best way to quickly address some pesky network problems is to scour Internet sites such as freshmeat.net and SourceForge.net for freeware applications.
Freeware, shareware and open source management applications offer network managers the opportunity to test software and its effectiveness on their nets before investing the cash to support pricey commercial licenses.
Last year, a Web search helped Rick Beebe, manager of system and network engineering for ITS-Med at the Yale University School of Medicine, find TTCP (http://www.netcordia.com/tools/tools-ttcp.shtml), a free network-throughput tester from Netcordia. Beebe wanted a tool that would help him figure out why two adjacent machines were experiencing vastly different transfer rates. One was getting 50Mbps rates and the other only 3Mbps, Beebe explained.
"In this case, I ran into a weird little problem that is kind of different from what I have in-house to track it down," Beebe said at the time. He used TTCP to test network throughput to the two machines and quickly resolved the problem.
"In a bigger use case, I may look for a commercial product, but I just searched online, found this and was able to fix the problem," Beebe said.
Jewels such as TTCP, Multi Router Traffic Graphic (MRTG (http://oss.oetiker.ch/mrtg/), Ethereal (http://www.ethereal.com/), Snort (http://www.snort.org/), plus many others, are considered essential in network managers' tool kits. Other applications such as OpenNMS (http://www.opennms.org/index.php/Main_Page) and Nagios (http://www.nagios.org/) promise -- with a bit of configuration upfront -- to manage distributed enterprise network using only open source. And now commercial vendors are getting in on the action. Newcomers such as Hyperic, Qlusters and Splunk have made open source versions of their commercial management applications available for download.