Configure network ubuntu/redhat

Redhat:
manually eth0: edit /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
HWADDR=00:e0:81:26:1e:9e
ONBOOT=no
BOOTPROTO=none
TYPE=Ethernet
NETMASK=255.255.255.0
IPADDR=192.168.1.214
GATEWAY=192.168.1.1

Using Commands: None-Gui command (system-config-network-tui)
GUI command: system-config-network &
Reference : http://www.cyberciti.biz/faq/rhel-centos-fedoracore-linux-network-card-configuration/

Ubuntu:
edit file: /etc/network/interfaces
iface eth0 inet static
address 192.168.1.100
netmask 255.255.255.0
network 192.168.1.0
broadcast 192.168.1.255
gateway 192.168.1.254

Restart the network.
sudo /etc/init.d/networking restart

Reference: http://www.cyberciti.biz/tips/howto-ubuntu-linux-convert-dhcp-network-configuration-to-static-ip-configuration.html