System Administration Guide, Volume 3

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. Each tool lets you select options and type in data that is then used to create the dhcptab and network tables used by the DHCP server.

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 is a series of dialog boxes that prompt you for the essential information required to configure a server: data store, 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, and 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 is a wrapper script for the dhtadm and pntadm commands. The dhcpconfig utility prompts you for server startup options such as the interval for reading the dhcptab, the timeout value for DHCP service offers, and so on. It obtains other information from the system files discussed in "Updating System Files and Netmask Tables". You cannot view the information it obtains from system files, so it is important that the system files be updated before running dhcpconfig.

Note that you can rerun dhcpconfig after updating system files and it will properly update the DHCP data.

Comparison of DHCP Manager and dhcpconfig

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

Table 9-2 Comparison of DHCP Manager and dhcpconfig


DHCP Manager 


Network information gathered from system 

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

You cannot see what information dhcpconfig is gathering. You must look at the dhcptab and network tables after they are created.

Configuration experience for user 

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

Prompts for all server options during configuration process. To change the options later, you must rerun dhcpconfig or use dhtadm and pntadm commands.

User input checking 

Checks validity of user input as it is entered. 

Does not check validity of user input as it is entered. 

The next chapter includes procedures for configuring your server using both DHCP Manager and dhcpconfig.