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:

PuTTY

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

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.