Why you need DHCP server?
DHCP is useful for fast delivery of client network configuration. When configuring the client system, the administrator can choose DHCP and not have to enter an IP address, netmask, gateway, or DNS servers. The client retrieves this information from the DHCP server.
DHCP is also useful if an administrator wants to change the IP addresses of a large number of systems. Instead of reconfiguring all the systems, he can just edit one DHCP configuration file on the server for the new set of IP address. If the DNS servers for an organization changes, the changes are made on the DHCP server, not on the DHCP clients. Once the network is restarted on the clients (or the clients are rebooted), the changes will take effect.
Step 1. Installing DHCP server
#apt-get install dhcp3-server
Once you press enter installation will start it will ask you some questions just you need to click ok for all three times
Step 2. Configuring DHCP server
The main Configuration file for DHCP server is
Before doing any changes take backup copy of this file and add the following lines