This document discusses planning, optimizing, and troubleshooting DHCP in a network. It covers creating a DHCP plan by designing DHCP infrastructures, scope reservations, options, and security. To optimize performance, the document recommends monitoring DHCP and adjusting the lease duration if the server is overloaded. Troubleshooting tools like Network Monitor, DHCP Audit Log, and IPConfig can help identify client-side, server-side, or infrastructure problems.

1. Objectives In this lesson, you will learn to: Create a DHCP plan Optimize DHCP performance Troubleshoot DHCP

2. Pre-assessment Questions Which of the following methods is used to allocate fixed TCP/IP addresses to the hosts? Manual addressing Dynamic Host Configuration Protocol (DHCP) reserved addressing Dynamic Host Configuration Protocol (DHCP) dynamic addressing Automatic Private IP Addressing (APIPA) A ________ resolves host names to IP addresses using DNS queries. Throughput Wire speed Utilization Number of collisions

3. Pre-assessment Questions (Contd.) Which of the following tools is used to determine the contents of frames on the network? Protocol analyzer Network management software Traffic–monitoring tool Handheld diagnostics tool Which of the following addressing structures is used for networks that are divided into subnets? Class-based Classless-based TCP/IP-based IPX-based

4. Pre-assessment Questions (Contd.) Consider the following statements: Statement A: The Automatic Private IP Addressing (APIPA) method enables a Windows Server 2003 computer to select an IP address automatically when a DHCP server is not available. Statement B: The Dynamic Host Configuration Protocol (DHCP) reserved addressing method enables the DHCP server to lease IP addresses from a range defined for each subnet. Which of the following is correct about the above statements? Statement A is False and Statement B is True . Statement A is True and Statement B is False. Both, Statement A and Statement B are True. Both, Statement A and Statement B are False.

5. Solutions to Pre-assessment Questions b. Dynamic Host Configuration Protocol (DHCP) dynamic addressing a. Throughput a. Protocol analyzer b. Classless-based b. Statement A is True and Statement B is False

6. Planning a DHCP Strategy IP addresses are assigned to hosts and devices on a network to facilitate communication between them. DHCP provides automatic IP addressing to the hosts on a network. The benefits of DHCP are: Enables you to efficiently administer and maintain the allocated IP addresses on a network Reduces the wastage of IP addresses by assigning IP addresses to mobile users for a short time-period Enables you to configure various DHCP options as per the requirements of the hosts on a network

7. Planning a DHCP Strategy (Contd.) To implement DHCP servers on a network, you need to perform the following tasks: Plan DHCP infrastructures Plan DHCP scope reservations Select the DHCP options and option classes Plan DHCP security

8. Planning DHCP Infrastructures You can select any one of the following DHCP infrastructures depending on the requirements of the organization: Centralized DHCP Infrastructure Distributed DHCP Infrastructure Mixed DHCP Infrastructure

9. Planning DHCP Scope Reservations DHCP scope defines the range of IP addresses that can be assigned to the hosts on a network. DHCP scope reservation enables you to decide the IP addresses to be assigned to the hosts and the devices on a network. You can plan for DHCP scope reservations when: The host needs to have a fixed IP address lease when it is started. Multiple DHCP servers provide service to the host. The host has not been assigned an IP address using DHCP.

10. Selecting DHCP Options and Option Classes Configuring DHCP options reduces the administrative overhead. The DHCP options that can be configured are: Routers DNS servers DNS domain WINS node type WINS server Gateway

11. Selecting DHCP Options and Option Classes (Contd.) DHCP option classes enable you to specify the DHCP configuration for users belonging to different categories. DHCP supports the following option classes: Vendor-defined classes User-defined classes

12. Planning DHCP Security DHCP servers provide a dynamic environment. Therefore, they need to be secured from unauthorized access and intrusions. You can select any of the following methods to secure DHCP servers in a network: Authorize DHCP servers in Active Directory Use Windows Server 2003 groups DHCP servers also need to be secured if you plan to set up the DHCP server on a screened subnet. This can be done by selecting any of the following methods: Reserving IP addresses in the scope Minimizing the available IP addresses

13. Practice- Creating a DHCP Plan Problem Statement You are the system administrator of BlueMoon Computers, Inc. You have already created a TCP/IP plan for the Virginia, Paris, and Geneva branch offices of BlueMoon Computers, Inc. You now need to automate the assignment of IP addresses ranging from 172.168.0.0 to 172.168.7.0 to the computers in these branches. For this, you need to implement DHCP servers on the network. The branch offices will be connected to the head offices using slow WAN links. In addition, the branch offices will have a combination of Windows NT hosts, Windows 2000, and Windows Server 2003 hosts. To implement DHCP, you need to create a DHCP plan for new branches.

14. Practice- Creating a DHCP Plan (Contd.) Solution Plan a DHCP infrastructure for the network Plan DHCP scope reservations for devices on the network Select DHCP options and option classes for the network Select a method to secure DHCP services

15. Optimizing DHCP The DHCP server assigns and reassigns IP addresses dynamically. Therefore, you need to regularly monitor the performance of DHCP and optimize it. To optimize DHCP performance, you need to first determine the cause of the low performance of the DHCP server and then address it. The cause of low performance can be: Unavailability of system resources Increased number of DHCP clients Increased network traffic Overload of DHCP requests

16. Changing Lease Duration The common cause of low DHCP server performance is increased amount of network traffic between the DHCP server and its clients. The network traffic can increase due to the number of lease requests and lease renewal requests sent by DHCP clients to the DHCP server. DHCP provides eight days as the default lease duration, which can be increased or decreased to optimize the performance of the DHCP server.

17. Practice- Changing Lease Duration to Optimize DHCP Performance Problem Statement You notice that the DHCP traffic has increased lately due to which the DHCP server on the network is overloaded. The employees of the marketing department use laptops. Laptop users do not use the intranet for a long duration at a stretch. Therefore, you plan to increase the availability of the intranet to other users.

18. Practice- Changing Lease Duration to Optimize DHCP Performance ( Contd.) Solution Modify the Lease Duration

19. Troubleshooting DHCP When monitoring DHCP performance, you can detect and troubleshoot problems related to assigning IP addresses or renewing IP address leases. Detecting and troubleshooting DHCP problems in the early stages helps you reduce the downtime of the DHCP server.

20. Selecting Troubleshooting Methods You need to determine the scope of the problem before troubleshooting a DHCP problem. The scope of a DHCP problem indicates the number of DHCP clients that have been affected by the problem. The DHCP problems can be classified as: Client-side problems Server-side problems Infrastructure problems

21. Selecting Troubleshooting Tools Windows Server 2003 provides the following tools to troubleshoot DHCP problems: Network Monitor DHCP Audit Log IPConfig

22. Practice- Troubleshooting DHCP Using Tools Problem Statement You have received complaints from employees that they are not able to access the file server on the network. When employees try to access the server, an error message, network path not found, appears. You identify the problem to be a DHCP-related issue. You need to plan a strategy to troubleshoot this problem.

23. Practice-Troubleshooting DHCP Using Tools (Contd.) Solution 1. Use the IPConfig command to troubleshoot this problem

24. Summary In this lesson, you learned that: DHCP provides automatic IP addressing to the hosts in a network. DHCP enables you to efficiently administer and maintain the allocated IP addresses in a network, reduce the wastage of IP addresses, and configure various DHCP options as per the requirements of the hosts in a network. To implement DHCP servers in a network, you need to plan the following: DHCP infrastructures DHCP scope reservations DHCP options and option classes DHCP security As the DHCP server assigns and reassigns IP addresses dynamically, you need to regularly monitor the performance of DHCP and optimize it. When monitoring DHCP performance, you can detect and troubleshoot problems related to assigning IP addresses or renewing IP address leases.

25. Summary (Contd.) DHCP problems can be classified as: Client-side problems Server-side problems Infrastructure problems Windows Server 2003 provides the following tools to troubleshoot DHCP problems: Network Monitor DHCP Audit Log IPConfig