Installation guide

116 Chapter 12. Dynamic Host Configuration Protocol (DHCP)
Table 12-1. DHCP Relay Agent Options
Argument Description
-i Names of the network interfaces to configure. If no interface is
specified, all network interfaces will be configured, eliminating
non-broadcast interfaces if it can.
-p Port on which dhcrelay should listen. The DHCP Relay Agent
transmits requests to the servers on this port and transmits responses to
the clients on the port one greater than this port.
-d Force dhcrelay to run in the foreground always.
-q Disable printing the network configuration of dhcrelay on startup.
12.3. Configuring a DHCP Client
The first step for configuring a DHCP client is to make sure the kernel recognizes the network
interface card. Most cards are recognized during the installation process, and the system is
configured to use the correct kernel module for the card. If you install a card after instal-
lation, Kudzu
1
should recognize it and prompt you to configure the corresponding kernel
module for it. Be sure to check the Red Hat Linux Hardware Compatibility List available at
http://hardware.redhat.com/hcl/. If the network card is not configured by the installation
program or Kudzu and you know which kernel module to load for it, refer to Chapter 24 for
details on loading kernel modules.
To configure a DHCP client manually, you need to modify the /etc/sysconfig/network
file to enable networking and the configuration file for each network device in the
/etc/sysconfig/network-scripts directory. In this directory, each device should have a
configuration file named ifcfg-eth0 where eth0 is the network device name.
The /etc/sysconfig/network file should contain the following line:
NETWORKING=yes
You might have more information in this file, but the NETWORKING variable must be set to
yes if you want networking to start at boot time.
The /etc/sysconfig/network-scripts/ifcfg-eth0 file should contain the following
lines:
DEVICE=eth0
BOOTPROTO=dhcp
ONBOOT=yes
You need a configuration file for each device that you want to configure to use DHCP.
If you prefer a graphical interface for configuring a DHCP client, refer to Chapter 6 for details
on using Network Configurator to configure a network interface to use DHCP.
1. Kudzu is a hardware probing tool run at system boot time to determine what hardware has been
added or removed from the system.