One of the most important skills in IT is networking. Even if you aren’t specializing in networking it is important to know a few things. So this is sort of a primer or cheat sheet for networking. The most used model for networking is the TCP/IP model. The basics can easily be summed in in a simple mnemonic Please Do Not Throw Sausage Pizza Away, or

Basically the data that is sent between 2 machines is encapsulated according to this model most layer encapsulating the one before it. If you can find fault in the physical layer or the application layer you might need to capture a packet and look at where the fault is in the network. Packet capture essentially lets you view a packet transmitted across the network. You can then view that packet and see thing like who it was meant for on the network and what data it contains.