Bibliography

Free

• http://www.aboutdebian.com/network.htm

Non-free

• stevens - 2012 - tcp ip illustrate volume 1 2nd edition

  Extremely clear and exemplified.

  Gives due emphasis to the key points.

  Great first book.

• dostalek - 2006 - Understanding tcp ip

  Explains the most important Internet protocol suite protocols deeply.

  Might not be the best first TCP IP book because it is a bit advanced, but it is a very good second one once you know the basics.