Configuring DHCP Client Hosts

Configuring hosts to use a DHCP server is a simple matter of setting options for the host's network interface device, such as an Ethernet card. For a Linux host, you can use a distribution network tool to set the host to automatically access a DHCP server for network information. On a network tool's panel for configuring the Internet connection, you will normally find a check box for selecting DHCP. Clicking this box will enable DHCP. For Red Hat, you can use the redhat-config-network tool and select the network device on the Devices panel and edit it. On the General panel, click the entry labeled Automatically Obtain IP Address Settings With, and be sure DHCP is selected from the pop-up menu. If you are connecting to an Internet service provider (ISP), under the DHCP Setting, click Automatically Obtain DNS Information From Provider. On Red Hat, the BOOTPROTO entry to DHCP will be set in that interface's network script in the /etc/sysconfig/network-scripts directory, such as ifcfg-eth0 for the first Ethernet card. You could also manually make this entry:

BOOTPROTO=dhcp

Be sure to restart your network devices with the network script to have the changes take effect.

The information that is being provided to a client by a DHCP server is listed in the client's /etc/dhcpc directory. Here you will find information files for the client's specific network device. For example, information provided for the first Ethernet device will be listed in the /etc/dhcpc/dhcpcd-etho.info file. You will find information such as the IP address, netmask, broadcast address, the hostname, domain name, and the DNS servers—all assigned by the DHCP server to the client.

On a Windows client, locate the TCP/IP entry for your network interface card, then open its properties window. Click the box labeled Obtain IP Address Automatically. Then locate the Wins panel (usually by clicking the Advanced button) and select DHCP as the protocol you want to use.