How to configure DHCP client on Redhat Linux 

What is DHCP ?

Dynamic Host Configuration Protocol (DHCP) is server/client protocol where DHCP server provides an  IP address automatically with necessary information  like subnet and gateway to DHCP clients.

How to configure DHCP client on Redhat Linux /Cent OS ? What are the files need to be edited to enable DHCP client ?  Here we are going to see how to setup DHCP client where your system is already running with static IP and also we are going to see about how to set persistent DHCP client.In the last part of article we will see how to re-new the IP address which is assigned by DHCP server.

edit eth0 configuration file to switch between static and dhcp networking configuration under RHEL / Fedora or CentOS Linux. Simply edit /etc/sysconfig/network-scripts/ifcfg-eth0 file.

Backup existing static configuration

First backup existing network configuration file using cp command:

# cp /etc/sysconfig/network-scripts/ifcfg-eth0 /root/ifcfg-eth0.bak

Configuring a DHCP Client

Setting up a Linux for dhcp can be done by editing file using a text editor such as vi:

# vi /etc/sysconfig/network-scripts/ifcfg-eth0

Following is sample static configuration:

DEVICE=eth0
BOOTPROTO=static
HWADDR=00:19:D1:2A:BA:A8
IPADDR=10.10.29.66
NETMASK=255.255.255.192
ONBOOT=yes
 Replace static configuration with DHCP:
 DEVICE=eth0
BOOTPROTO=dhcp
HWADDR=00:19:D1:2A:BA:A8
ONBOOT=yes

Save and close the file. Just restart network service:

# /etc/init.d/network restart