The DHCP Handbook

The Dynamic Host Configuration Protocol (DHCP) provides a way to automate and manage the network configurations of devices that use the TCP/IP protocol suite. Without DHCP, network administrators must manually enter in IP addresses for each computer and network device and then manually change that address each time the device is moved to a different part of the network. The DHCP Handbook, Second Edition is a complete reference for understanding DHCP, deploying and managing DHCP services, and debugging problems with DHCP clients and servers. Chapters devoted to failover, authentication, Windows 2000, DHCPv6, and DHCP/DNS interaction reflect the recent updates to the standard and issues that are most pertinent to network planners and administrators. Throughout the book, the authors are careful to balance conceptual discussions of DHCP with detailed implementation examples and practical advice.

The authors of this text, Ralph Droms and Ted Lemon, bring extensive expertise and experience with DHCP and IP networking to this book. In this text, the authors combine their insights to create a unique perspective on the theory and design of the DHCP specification, as well as the practical aspects of implementing a DHCP server and running a DHCP service.

Ralph Droms, Ph.D., organized the DHCWG with Phil Gross in 1989. He has chaired the working group since its inception and is a key contributor to the design and development of DHCP. Ralph is also editor of the DHCP RFCs and continues to participate in the evolution of DHCP. Since joining Cisco in 2000, Ralph has continued his work on DHCP and network management. Previously, he was a member of the Computer Science Department faculty at Bucknell University, where he guided students through the study of TCP/IP internetworking, operating systems, and computer architecture. Ralph has also been a member of the computer science faculty at Pennsylvania State University, and he was on the research staff at IBM and Burroughs (now Unisys).

As a consultant in network architecture and infrastructure design, Ralph has worked with large and small companies on a variety of TCP/IP issues, including network architecture, server strategies and configurations, and the use of DHCP, DNS, and other technologies in network management. Ralph served as co-director of the computer center at Bucknell, where he supervised the design and implementation of the campuswide multiprotocol network.

Ralph lives with his wife and two daughters in Westford, Massachusetts. You can reach him at rdroms@cisco.com.

Ted Lemon first encountered DHCP while working as a network administrator at Digital Equipment Corporation in the early 1990s. In 1996 Paul Vixie of the Internet Software Consortium became concerned that there was no high-quality open-source implementation of DHCP, and he asked Ted if he would be willing to produce one. The ISC DHCP distribution was the result.

As part of the work of producing the ISC DHCP distribution, Ted has been active in the IETF DHCWG since 1996. Along with Ralph, Bernie Volz, and Jim Bound, Ted is working on a new version of DHCP for IPv6, as well as extensions to the DHCP protocol for IPv4.

One of the important ways that open-source projects are improved is through examination of user feedback for ways to do things better and for common problems that users have. Ted has had a great deal of experience helping people with common problems with the various aspects of DHCP. His motivation in working on this book has been to help people who need to use DHCP to learn what they need to know to install and manage a DHCP installation without sending him e-mail.

Ted currently works for Nominum, Inc., a leading vendor of DHCP and DNS solutions.