Three network tools I couldn't live without

I recently decided to rebuild my Windows machine. I find it's something that needs doing every six months or so. Luckily, I now run my Windows machine as a VMware virtual machine so I don't have to start the re-install from scratch; I just roll back to a snapshot taken when it was nice and clean. I can then re-install what I consider to be essential tools and enjoy the machine running much more quickly without all of the junk that tends to build up over time.

What are the first applications I re-install? What are those applications we don't always think about until they're gone? Here are my top three networking tools:


I'm sure I've talked about this one before. PuTTY must be one of the best tools available for an administrator who may need to log on to a Linux/BSD server from a Windows machine. PuTTY is a GUI client application that enables remote access via SSH, Telnet, and Rlogin protocols. While there are plenty of other clients available, PuTTY always comes up on top. It's free, lightweight, easy to use, and extremely effective; what more could you ask for?

Download PuTTY from here for free. Don't worry about the myriad of download options. I usually just go for the Windows installer.

Wireshark Billed as "The World's most popular Network Protocol Analyser" and formerly known as Ethereal--Wireshark was created when Gerald Combs (creator of Ethereal) went to work for CACE Technologies (creators of the WinPcap library). The Ethereal trademarks could not be taken with him so a ‘fork' was created and the name was changed to Wireshark.

So what does it do? Wireshark is a protocol analyser. Similar in many ways to tcpdump; Wireshark adds an easy-to-use GUI and various sorting/filtering options. As Wireshark actually ‘understands' the protocols, it's able to rebuild and display data streams from the captured packets, which can really help while trying to track down that intermittent bug.

What makes Wireshark special? It runs on Windows, OS X, Linux, and UNIX; it supports hundreds of protocols; it has powerful filtering options; and it can be used to analyse data caught ‘on the fly' or saved previously with tcpdump. I have been told Wireshark is great for VoIP analysis, but I haven't used it for that.

Oh, did I mention it's free too? Download Wireshark here.


Nessus is a top class vulnerability scanner produced by Tenable Network Security. Estimated to be used by more than 75000 organisations worldwide--Nessus is said to be the worlds' most popular vulnerability scanner.

Formerly an open source project, Nessus was moved to a proprietary license on the release of version 3; the scanning engine is still free, although support and up-to-the-minute vulnerability definitions are charged for. Those who don't want to pay still get the updates seven days after their release.

Nessus starts by performing a port scan on the chosen host or network. It then probes open ports to try and determine which services are running and tests those services against known vulnerabilities. I think Nessus is a great tool for testing the resilience of your network. The reports it generates are highly detailed and make a good basis for any status reports you may need to produce.

Nessus is available for OS X, Linux, BSD, and Windows. Download Nessus here (it's free but you will need to activate).

Of course there are many great network related tools available and everybody will have their own opinion on which is the most important; after all, everyone's requirements are different. Despite being a Windows-only application and being very basic when compared to Wireshark and Nessus; PuTTY is still the tool I just couldn't do without.

What are your top networking tools?