Hardware versus software sniffing

You may be thinking, how do we sniff? Well, we have both hardware and software solutions to deal with. I'm going to warn you ahead of time, the hardware side is not cheap. On the hardware side of things, we have protocol analyzers. These devices are designed to monitor network traffic. This would be the poor man's version:

Figure 10.2 – Various sniffing devices

I had an opportunity to play around with one, the Fluke pictured in the middle and at the bottom in the preceding figure. It's such a fantastic little device. They're not only used to monitor but also analyze the data. With the Fluke, we can see how long the cable run is. If there were a break, we would see how far down the cable it was broken. You could also analyze the top protocols being used on the network. A multi-port testing system device such as the N2XN5540A would allow you to monitor and verify the performance of networks and devices...