The network, and the connected nature of things is what allows us as penetration testers to attempt to compromise the security of a company without going anywhere near it. There are other aspects to full scale penetration testing as I’ve alluded to before – with social engineering and physical attack ( lock picking, not baseball bat ) parts of such a scope – but a majority of the work is computer and network based. To that end, a good understanding and working knowledge of networking is pretty much a job pre-requisite. So, rather than giving you a lesson myself, I’ll give you a quick and dirty set of online references – this won’t make you an expert by any stretch of the imagination, but hopefully it will get us through the rest of this section without too much head scratching…