System Administration Guide: IP Services

Selecting the Tool for Configuring DHCP

After you have gathered information and made decisions as outlined in the previous sections, you are ready to configure a DHCP server. You can use the graphical DHCP Manager or the command-line utility dhcpconfig to configure a server. DHCP Manager lets you select options and enter data that is then used to create the dhcptab and network tables used by the DHCP server. The dhcpconfig utility requires you to use command-line options to specify data.

DHCP Manager Features

DHCP Manager, a Java-based graphical tool, provides a DHCP Configuration Wizard, which starts automatically the first time you run DHCP Manager on a system that is not configured as a DHCP server. The DHCP Configuration Wizard provides a series of dialog boxes that prompt you for the essential information required to configure a server: data store format, lease policy, DNS/NIS/NIS+ servers and domains, and router addresses. Some of the information is obtained by the wizard from system files, and you only need to confirm that the information is correct, or correct it if necessary.

When you progress through the dialog boxes and approve the information, and the DHCP server daemon starts on the server system, you are prompted to start the Add Addresses Wizard to configure IP addresses for the network. Only the server's network is configured for DHCP initially, and other server options are given default values. You can run DHCP Manager again after the initial configuration is complete to add networks and modify other server options.

dhcpconfig Features

The dhcpconfig utility supports a list of options that allow you to configure and unconfigure a DHCP server, as well as convert to a new data store and import/export data to and from other DHCP servers. When you use the dhcpconfig utility to configure a DHCP server, it obtains information from the system files discussed in Updating System Files and Netmask Tables. You cannot view and confirm the information it obtains from system files as you can with DHCP Manager, so it is important that the system files be updated before you run dhcpconfig. You can also use command-line options to override the values dhcpconfig would obtain by default from system files. The dhcpconfig command can be used in scripts. Please see the dhcpconfig man page for more information.

Comparison of DHCP Manager and dhcpconfig

The following table summarizes the differences between the two server configuration tools.

Table 8–4 Comparison of DHCP Manager and the dhcpconfig Command


DHCP Manager 

dhcpconfig With Options

Network information gathered from system. 

Allows you to view the information gathered from system files, and change it if needed. 

You can specify the network information with command-line options. 

Configuration experience for user. 

Speeds the configuration process by omitting prompts for nonessential server options by using default values for them. Allows you to change nonessential options after initial configuration. 

Fastest configuration process, but user may need to specify values for many options. 

The next chapter includes procedures you can use to configure your server with both DHCP Manager and the dhcpconfig utility.