1 Objectives Discuss the basics of Dynamic Host Configuration Protocol (DHCP) Describe the components and processes of DHCP Install DHCP in a Windows Server 2008 environment Configure the DHCP server Administer DHCP on clients and servers Troubleshoot DHCP

2 Basics of DHCP DHCP –Layer 4 protocol –Clients use UDP port 68 –Servers use UDP port 67 –Broadcast communication

3 DHCP Components and Processes DHCP lease: IP address is loaned to a DHCP client Lease duration DHCP scope –A range of IP addresses

4 DHCP Options Clients not only get IP address, subnet mask, but also default gateway (router) and DNS servers

Leasing an IP Address

Setting a Client to Obtain an IP Address from a DHCP Server

Set up DHCP Server Add DHCP Server Role. Authorize the DHCP server. Configure a scope or pool of addresses. Set up Exclusion and Reservation Configure global and client scope.

Install DHCP Server

Authorize DHCP Server

Configure DHCP Scope

11 Configuring Exclusions Exclusions are created so that: –Static IP addresses for devices such as routers, printers, or other network devices are not assigned Common practice –Create exclusionary ranges at the beginning and end of a scope range

12 Creating Reservations Reservations –Used in DHCP to give a DHCP client a static IP address without manually configuring the address on the client

Configuring DHCP Options DHCP can hand out a variety of other IP configuration options such as DNS, Default Gateway (router)

Vendor and User Classes Used to differentiate between clients within a scope  Users get different scope option based on their class Vendor classes are based on the operating system User classes are defined based on network connectivity or the administrator You can use the ipconfig /setclassid command to set the DHCP user class ID

Vendor and User Classes (continued)

Configuring a DHCP Relay DHCP packets cannot travel across a router A relay agent is necessary in order to have a single DHCP server handle all leases Relay agents receive broadcast DHCP packets and forward them as unicast packets to a DHCP server The DHCP relay cannot be installed on the same server as the DHCP service

Configuring a DHCP Relay (continued)

20 Using netsh Syntax for creating a DHCP reservation netsh Dhcp Server Scope add reservedip c40fb6a MSN-SRV-150 Syntax for creating a DHCP exclusionary range netsh Dhcp Server Scope add excluderange

21 DHCP Client Configuration DHCP Client service –Responsible for the DHCP configuration process on a client machine Fault tolerance and DHCP –Microsoft recommends using an 80/20 rule for splitting scopes between two servers for fault tolerance –80/20 rule 80 percent of a scope’s total IP range is hosted on your primary DHCP server, while the remaining 20 percent is hosted on your secondary DHCP server

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23 DHCP console statistics –Server statistics: broader and provide a more comprehensive picture of the status of your DHCP server –Scope statistics: display information about each scope DHCP audit log –Lists detailed information about events occurring on a specific day, including Event ID, Date and time Event description, IP address Host name, MAC address Monitoring Reliability and Performance

Backup and Recovery Automatic backup –Windows Server 2008 performs an automated backup of the DHCP database every 60 minutes Manual backup –Stored in the %systemroot%\systemroot\dhcp\backup folder Restoring the DHCP database from a backup –You can restore a DHCP database from an offline backup when you are building a new DHCP server 24

Troubleshooting DHCP Reconciling the database –Validates the DHCP database by comparing it with the Registry values of the operating system to verify that the database contains the most current data To determine the running services on a system –Enter the net start command at a command prompt To stop a running service net stop “DHCP Server” or “DHCP Client” net start “DHCP Server” or “DHCP Client” 25

Troubleshooting DHCP Clients: ipconfig –ipconfig /release –ipconfig /renew –ipconfig /flushdns 26

27 Using DHCPv6 IPv6 clients –Use DHCP to receive IP address and configuration information from an IPv6 router on their network Implementing DHCPv6 requires –Configuring your router to forward all autoconfiguration requests to an available DHCPv6 server –Disabling stateless mode on your Windows Server 2008 DHCP servers