Red Hat ENTERPRISE LINUX 3 System Administration Manual page 198

182
Refer to the
dhcpd.conf
There are two types of statements in the configuration file:
Parameters — state how to perform a task, whether to perform a task, or what network configuration
•
options to send to the client.
Declarations — describe the topology of the network, describe the clients, provide addresses for
•
the clients, or apply a group of parameters to a group of declarations.
Some parameters must start with the
figure DHCP options; whereas, parameters configure values that are not optional or control how the
DHCP server behaves.
Parameters (including options) declared before a section enclosed in curly brackets ({ }) are consid-
ered global parameters. Global parameters apply to all the sections below it.
Important
If the configuration file is changed, the changes do not take effect until the DHCP daemon is restarted
with the command
In Example 25-1, the
options are used for any
time-offset
As shown in Example 25-1, a
every subnet in the network. If it is not, the DHCP server fails to start.
In this example, there are global options for every DHCP client in the subnet and a
Clients are assigned an IP address within the
subnet 192.168.1.0 netmask 255.255.255.0 {
option routers
option subnet-mask
option domain-name
option domain-name-servers
option time-offset
range 192.168.1.10 192.168.1.100;
}
Example 25-1. Subnet Declaration
All subnets that share the same physical network should be declared within a
laration as shown in Example 25-2. Parameters within the
declarations are considered global parameters. The name of the
subnet
a descriptive title for the network such as test-lab to describe all the subnets in a test lab environment.
shared-network name {
option domain-name
option domain-name-servers
option routers
more parameters for EXAMPLE shared-network
subnet 192.168.1.0 netmask 255.255.255.0 {
parameters for subnet
Chapter 25. Dynamic Host Configuration Protocol (DHCP)
man page for details about the different modes.
option
service dhcpd restart
,
routers subnet-mask
host
can be declared. A
subnet
keyword and are referred to as options. Options con-
.
,
domain-name
statements declared below it.
subnet
.
range
192.168.1.254;
255.255.255.0;
"example.com";
192.168.1.1;
-18000;
shared-network
"test.redhat.com";
ns1.redhat.com, ns2.redhat.com;
192.168.1.254;
,
domain-name-servers
declaration must be included for
range
# Eastern Standard Time
shared-network
but outside the enclosed
shared-network
, and
declared.
dec-
should be