MCSE/MCSA Exam 70-291 Exam Prep: Implementing, Managing, and Troubleshooting DHCP

Objectives

Microsoft lists the following objectives for the DHCP portion of the "Implementing, Managing, and Maintaining IP Addressing" section of Exam 70-291, "Implementing, Managing, and Maintaining a Microsoft Windows Server 2003 Network Infrastructure":

Manage DHCP.

• Manage DHCP clients and leases.
• Manage DHCP Relay Agent.
• Manage DHCP databases.
• Manage DHCP scope options.
• Manage reservations and reserved clients.
• One of the first few network services you will likely deploy and configure when rolling out a production Windows Server 2003 network is the DHCP service. DHCP is highly integrated with both Active Directory and the dynamic DNS (DDNS) service. To meet this objective, you must have a thorough understanding of the workings of DHCP and also how to configure it for use in a network.

Troubleshoot DHCP.

• Diagnose and resolve issues related to DHCP authorization.
• Verify DHCP reservation configuration.
• Examine the system event log and DHCP server audit log files to find related events.
• Diagnose and resolve issues related to configuration of DHCP server and scope options.
• Verify that the DHCP Relay Agent is working correctly.
• Verify database integrity.
• Installing and configuring the DHCP service does not relieve you of monitoring and managing it over time. The ability to monitor, manage, and troubleshoot the DHCP service on a network is critical to the ongoing health of the network as a whole. You should be able to use all the tools available to you to ensure that the DHCP service is operating properly, providing service to network clients.

Outline

Study Strategies

• Be sure you understand what DHCP is, how it works, why it was created, and what enhancements Microsoft Windows Server 2003 DHCP server service adds to the protocol. DHCP has been used in Transmission Control Protocol/Internet Protocol (TCP/IP)-based networks for quite a while. Microsoft has extended the functionality of DHCP as part of its Windows Server 2003 operating system. DHCP is used to dynamically allocate IP addresses, and it also plays a critical role in registering hosts with the Domain Name Service (DNS).
• Be sure you understand the types of scopes that Windows Server 2003 DHCP server service supports, how each works, and when you should use each in a production environment.
• Get your hands dirty. The Step by Step exercises throughout this book provide plenty of directions and exercises, but you should go beyond those examples and create some of your own. If you can, experiment with each of the topics we discuss in this chapter to see how they work and why you would use each one.

Introduction

TCP/IP is the de facto standard for computer networking and appears to have no challengers in the networking protocol arena. If you are going to work with Windows Server 2003, you should expect to work with TCP/IP. One of the keys to successfully working with TCP/IP is having an understanding of the concept of TCP/IP addresses. The designers of TCP/IP wanted an identification scheme that was independent of any one computer or network equipment design, so they established a scheme of IP addresses.

If you've ever surfed the Web, you have probably seen IP addresses at one time or another (numbers such as 192.168.144.77). As you administer TCP/IP on a network, a considerable part of your time will be devoted to IP address assignment because IP addresses don't just magically get assigned to network hosts—they have to be provided through manual configuration or some other means. When a computer is added to a network, it needs an IP address to communicate on that network. When the computer moves to a new location, it is likely to need a new IP address. If you are just starting out with managing a large TCP/IP network, you might find the notion of managing all those addresses a bit daunting. If you move a DNS server to a new subnet, you may have to reconfigure every client computer. If you move a client computer to a new subnet, you may have to update its IP address. This does not endear you to road warriors who travel among several offices, especially those who are regional managers. If you manually manage IP addresses, almost any change to the network will require a visit to one or more computers to update TCP/IP configurations—not a happy prospect. Fortunately, the people who brought us DNS to replace the hosts file also came up with a solution to this dilemma.

DHCP was the Internet community's answer to dynamically distributing IP addresses. DHCP is open and standards-based, as defined by the Internet Engineering Task Force (IETF) in their Requests for Comments (RFCs) 2131 and 2132. (The IETF is the main standards organization for the Internet.) This chapter examines the basics of DHCP as it applies to you, the systems administrator, and how you can use it to make your life and your network better.