The CTDP Network Certification Reference Introduction: "This is a reference for those interested in learning and referencing information relevant to obtaining a professional certification. This reference is for the networking side and does not cover operating systems or programs that are used on them any more than is necessary. This material is intended as a reference, not specifically as a learning tool. It repeats some of the information in the networking guide with the purpose of being a single reference as an aid for a network certification examination. "