If you’re not familiar with Smoothwall Express it is a firewall product that turns a PC into a dedicated firewall appliance;  it consists of a tightly configured and hardened Linux distribution with applications installed to convert even a very old PC into a surprisingly powerful firewalling and connection sharing device.  It can handle up to four dedicated network zones which give you much more control than you would with most other dedicated networking hardware; it can also be customised with “mods”, special alterations which can be used to add or change functionality to suit your needs (some are referred to as “homebrew mods” which are developed by Smoothwall’s excellent support community).

NetTraf - Live Traffic Monitor

One of my favourite is the mod “Nettraf” – short for Net Traffic.  It presents a small icon on your windows task bar which gives you a live graph of what is happening on any particular interface; for instance you can install it and watch the traffic load on the main internet link to see if it is being heavily utilised or not.

This can be very useful if you have a number of machines connected to Smoothwall – if one is aggressively using the connection it can give you an indication of why others are slowing for instance;  this is a surprisingly useful piece of information particularly if it is live, i.e. constantly being displayed on your desktop.

There are two parts to Nettraf – a component installed on Smoothwall itself and another which you run on your Windows desktop (this article only concerns the windows version).  

Nettraf is rather old now but can be still found on Sourceforge;  I have tested it on every version of windows from 2000 to Windows 7, I belive it should work on Windows 8.x but I have not personally tested it myself.