In this video it is explained how to subnet from a /24 network to a /25 network. Pdf version of the video: https://docs.google.com/file/d/0BwdCenzqdAJsa1dYeTZMWktHWFk/edit?usp=sharing Exercises: https://docs.google.com/file/d/0BwdCenzqdAJsRzFLTWxmRmFITVE/edit?usp=sharing