I have never read a more concise but clearly written technical book, and the code looks beautiful too. Pretty much every software engineer needs this book.
If you absolutely know what you are doing it reduces the solution time for most known problems from hours to minutes. If you are not all that clued up about IP but want/need to be, this is the book. Fundamental Networking in Java could just as easily be just called Fundamental Networking.
I expect this book will become the standard text in Software Engineering courses on Networking. And if your course has a different text, this book is probably a better choice. It will be one of the very few textbooks that will survive your transition into the working world.
And the beauty of this book is that because it is written in crystal clear english it is also very useful to a much wider audience - technology manager, business analyst, etcetera.