For those moments you want some technical breakdowns of documents packetlife has the best cheat sheets I have ever seen. I wish I had these during my networking classes, it would have been easy to remember all the different routing protocols and the best part is the ports cheat sheet, they really go into a lot of detail, for any techi there are some really useful documents. They have done an excellent job of simplifying and presenting the information, color coding, and relating the right info.

Link: PacketLife