Reader favorites: 10 great free network tools

SNMP Traffic Grapher

Like its big cousin, MRTG, SNMP Traffic Grapher (STG) takes SNMP data and presents it in a graph form. But it doesn't need a back-end Web server, nor does it need to be refreshed every time statistics are updated. Think of STG as a real-time MRTG application. In fact, it was developed to be a companion to MRTG.

STG can provide timely information just when you need it most. Think of when you want to make a network change and you're worried how it will affect traffic. Maybe you're loosening restrictions and afraid the egress bandwidth will spike. Or perhaps you're activating VPN on your firewall and are worried that CPU utilization will go up.

STG, like MRTG, can graph any SNMP MIB variable, but the difference is that information is displayed in real time. That's its main strength. STG is as configurable as it needs to be; enter the MIB value, the polling time and the display output. That's all.

Like MRTG, STG displays in a graphical format any SNMP MIB variable, such as inbound and outbound traffic as shown here.

STG is invaluable not so much for trending (use MRTG for that) but for checking in real time how network changes affect performance. We often have to make changes we don't want to in the middle of the business day. Knowing how that affects performance before the end user notices problems is essential.

Despite its usefulness, there doesn't appear to have been any recent development on STG. However, others have created similar tools such as Paessler Router Traffic Grapher. I discovered this while researching this article and plan to evaluate it at a future date.

What else?

Don't forget that it may be worthwhile to learn rudimentary Linux administration skills so you can use other sophisticated open-source tools to manage your network.

Everyone has their favorite tools in their bag of tricks. Have we missed one of yours? Perhaps you have evaluated some of the reviewed tools or others mentioned in this article and want to share what you've learned. If so, let us know in the article comments section.

Greg Schaffer is a freelance writer in Tennessee. He has over 15 years of experience in networking, primarily in higher education. He can be reached at newtnoise@comcast.net.