The basics for any network based on *nix hosts is the Transport Control Protocol/ Internet Protocol (TCP/IP) combination of three protocols. This combination consists of the Internet Protocol (IP),Transport Control Protocol (TCP), and Universal Datagram Protocol (UDP).
By Default most of the users configure their network card during the installation of Ubuntu. You can however, use the ifconfig command at the shell prompt or Ubuntuâ€™s graphical network configuration tools, such as network-admin, to edit your systemâ€™s network device information or to add or remove network devices on your system
Configuring DHCP address for your network card
If you want to configure DHCP address you need to edit the /etc/network/interfaces and you need to enter the following lines replace eth0 with your network interface card
sudo vi /etc/network/interfaces
# The primary network interface – use DHCP to find our address
iface eth0 inet dhcp