How to Setup a DHCP Server on CentOS 6.2

Wednesday, June 12, 2013

How to Setup a DHCP Server on CentOS 6.2

In this scenario, we have a CentOS server with two network cards, but it will only listen the dhcp request on one card (eth1).

Here is the configuration of eth1 interface:

cat /etc/sysconfig/network-scripts/ifcfg-eth1

CentOS as DHCP Server:

To install dhcp server, enter the following command at a terminal prompt:

sudo yum -y install dhcp

To make the dhcp server start at boot time, use this commands:

sudo chkconfig dhcpd on

As we are using more than one network card(s) in our CentOS server, so we need to specify on which interface our server will be listen for dhcp request. (By default, it listens on eth0).

You can change this by editing /etc/sysconfig/dhcpd file:

sudo nano /etc/sysconfig/dhcpd

Add the name of the interface on which you want that your server will listen for dhcp request (In my case, it is eth1):

DHCPDARGS=eth1

Copy the default configuration file from /usr/share/doc/dhcp-versidhcp/dhcpd.conf.sample to the /etc/dhcp/dhcpd.conf :

sudo cp /usr/share/doc/dhcp-*/dhcpd.conf.sample /etc/dhcp/dhcpd.conf

Now we will change the default configuration by editing /etc/dhcp/dhcpd.conf, I normally delete everything inside the file and manually add the configuration that suits my needs :-)

sudo nano /etc/dhcp/dhcpd.conf

Here is my dhcpd.conf file, you need to change it according to your needs:

ddns-update-style none;
authoritative;
log-facility local7;
default-lease-time 600;
max-lease-time 7200;
option subnet-mask 255.255.255.0;
option broadcast-address 172.16.10.255;
option routers 172.16.10.1;
option domain-name-servers 172.16.1.1;
option domain-name "centos.local";
subnet 172.16.10.0 netmask 255.255.255.0 {
 range 172.16.10.10 172.16.10.100;
}