Edit give IP address to /etc/sysconfig/network-scripts/ifcfg-eth0. Change BOOTPROTO to static, and ONBOOT to yes, and add IP address, Gateway, and Netmask.

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

DEVICE="eth0"
TYPE="Ethernet"
UUID="318d7785-7e38-4865-bd05-7fe97ccf0f47"
HWADDR=00:0C:29:05:F5:66
BOOTPROTO="static"
ONBOOT="yes"

IPADDR=73.123.123.2
NETMASK=255.255.255.248
GATEWAY=73.123.123.1

Add DNS Server, you can use generic DNS Server such as Google DNS 8.8.8.8 and 8.8.4.4

vi /etc/resolv.conf

nameserver 8.8.8.8
nameserver 8.8.4.4

Restart Network

/etc/init.d/network restart

Try to ping Google.

ping google.com

Done.