All praises and thanks go to God almighty for giving me the opportunity to complete this project. Without His mercy and His compassion, the writing of this book simply would not be possible. I can never be humble enough to show my gratitude to Him for everything He blessed me with.
A big thanks goes to my manager, Tony Moreland, who helped me so much during this project. He is one of the best technical managers (if not the best) at Cisco. Throughout the writing of this book, he has been as supportive and flexible as he could be. I could not have asked more. Thanks to Dale Miller, Director of HTTS, and Curtis Hill, Senior Director, for giving me the opportunity to learn and grow in the HTTS organization. Their unmatched and superior leadership makes HTTS a fun place to learn, work, and grow professionally.
Special thanks go to Technical Reviewers Qiang Huang, Nadeem Khawaja, and Jonathan Limbo. They are all my friends, colleagues, and some of the finest troubleshooters for Security/VPN products in the industry. Thanks for taking time and editing the book character by character for technical accuracy. You guys are simply superb!!
This acknowledgment would not be complete without mentioning two names from Cisco PressAcquisitions Editor Michelle Grandin, who trusted me with this project, and helped me tremendously during the initial phase of writing, and Developmental Editor Betsey Henkels, who edited and corrected the writing of the book character by character. I am impressed with her level of energy and patience in this endeavor. I don't want to miss the opportunity to thank other Cisco Press folks involvedExecutive Editor Mary Beth Ray, for keeping me on track throughout the writing process; Executive Editor Brett Bartow, for trusting me with the project; Christopher Cleveland, Sr. Development Editor, for his careful editing; and Marc Fowler, Project Editor, for all of his flexibility.
Technical contents of the book are based on developers' discussions, internal training materials, chalk talks, networkers presentations, and my on-the-job training. Several engineers' names come to mind who helped me in developing my technical skills, which directly and indirectly influenced the contents of the book. Among many, some of them are Christopher Paggen (two case studies in Chapter 4 are taken directly from his notes); David White, Jr. (Dave is a true expert in PIX/ASA; Chapter 3 would have not been completed without borrowing some great content from Dave's work); Mike Sullenberger; and Frederic Detienne for DMVPN and VPN in general. I would like to thank those individuals, among others, whose names are unknown.
On the family front, I would like to thank my younger brother, Tipu, for encouraging me to move into the field of networking; my elder sister, Parvin, and her husband, Ripon, for their love and affection; and my uncle, Abdul Mannan, whose guidance helped in building the foundation of my educational background.
This book is the result of the direct and indirect contributions of all these individuals. I am ever grateful to them.