Assuming you already have an ETH0 configured and working, log in at the console and configure it just like a normal RHEL/CentOS nic configuration:
- cp /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/ifcfg-eth1
- vim /etc/sysconfig/network-scripts/ifcfg-eth1
- Update the ETH # to the next in line. (ETH0 to ETH1…)
- Update the correct IP & Subnet
- :wq
- service network restart
- run ifconfig to ensure the settings have taken effect