Favorite cheap network tools

Network World bloggers love to dish about their favorite free or low-cost network tools.

We asked our bloggers to give us a list of the free or nearly free network tools they love. They had tons of them, ranging from ways to track network device configurations to ways to keep data synched between multiple devices.

The list is more or less organized by the blogger who recommended them, although in some cases (Wireshark, iPerf) more than one blogger recommends the tool. We hope you find, and try, some goodies on the list.

Scott Hogg

We asked our bloggers to give us a list of the free or nearly free network tools they love. They had tons of them, ranging from ways to track network device configurations to ways to keep data synched between multiple devices.

The list is more or less organized by the blogger who recommended them, although in some cases (Wireshark, iPerf) more than one blogger recommends the tool. We hope you find, and try, some goodies on the list.

Scott Hogg

Scott Hogg loves:

Really Awesome New Cisco confIg Differ RANCID

Not everyone can afford Solarwinds Orion Network Configuration Management (NCM) or CiscoWorks LAN Management Solution (LMS) to manage changes to their network device configurations. That is why Really Awesome New Cisco confIg Differ (RANCID) continues to be a favorite tool among network engineers. RANCID is easy to install and configure on a variety of operating systems. RANCID's real benefit to network administrators is its ability to back up network device configurations and help you investigate changes to your environment. Since most network issues are attributable to human error, it is valuable to have that historical record of what changed. Configuration management is one of the best practices that typically go by the wayside for organizations on a limited IT budget. Oftentimes the root cause of a problem can be easily found within that list of differences between yesterday'ss and today's configuration.

JMeter

You may also need to assess application performance because people tend to "blame it on the network." To validate that a problem is not within the network domain and assess application performance, a tool like JMeter comes in handy. JMeter is a simple Java application that can perform load tests on a wide variety of web-based applications, FTP, and other protocol traffic. It takes just a moment to download the package, unzip it into a directory, run the JMeter application and get started configuring your test. Just make sure you already have Java Runtime Environment (JRE) installed. There are a wide variety of tests and test options. The easiest way to get started is to first create a Thread Group and then apply your tests beneath that. Then you can run the test and look at the results/reports that you configured for your test. There are many tutorials and examples out there to help your learning curve. JMeter can be configured for multiple threads and can really generate a lot of traffic and help you determine how many connections per second your systems are capable of serving.

Dynamips, Dynagen, GNS3

Fewer of us have lab setups as extensive as Scott Morris's mega-lab. Indeed, many network administrators do not have access to a suitable lab at all. Their organizations are not financially capable of providing lab devices that are similar to those devices in the production network. However, it is often useful to configure a simple little scenario to validate an idea or to prototype a solution. Dynamips is a system that allows you to emulate Cisco IOS image files and run them in a configurable environment. You can use Dynagen 1.11.7 or Graphical Network Simulator (GNS3) 0.7.2 front-ends that utilize Dynamips' underlying capabilities to make it easy to configure a virtual lab of Cisco routers joined together. Once the lab devices and interconnections are defined within the text file, the lab can be started and you can console to your routers and commence the fun. Just be sure you are cognizant of the CPU and memory resource constraints of building a large lab environment and review the tutorial to set the idle-PC value. If you are studying for any Cisco certification that requires hands-on experience, then these free tools are invaluable.