Installing and Administering Internet Services

Chapter 6 199

DHCP

Conﬁguration Overview

The DHCP server is conﬁgured and administered through SAM (or by

editing the ﬁles /etc/bootptab and /etc/dhcptab, described later).

DHCP consists of three branches of conﬁguration, each of which involves

a different method of clients receiving booting information:

• DHCP Device Groups

• Fixed-Address Devices

• Devices Booting From Remote Servers

DHCP Device Groups

DHCP allows you to conﬁgure groups of devices, specifying a unique IP

address range for each group conﬁgured. Each device in a speciﬁc group

is automatically assigned an available IP address from its group upon

requesting booting information.

By creating various groups of devices you can compose each group with a

device type speciﬁc to that group. For example, you may want one group

to contain nothing except printers, and you may want another group to

contain a certain type of terminal.

Figure 6-1 Devices Can be Conﬁgured as Part of a DHCP Group

In the drawing, assume that a particular group has been conﬁgured so

that Client1, Client2, and Client3 all belong to this group. This means

that each device in this group will have the same group name and will be

given an IP address that is within the group’s IP address range. The IP

addresses within the group’s range make up what is known as a pool of

addresses. When Client1, Client2, or Client3 perform a boot request,

they will automatically be assigned an IP address not already in use

from this pool.

DHCP

Client1

Client2

Client3

Server

DHCP