centos

The network cards configured were not the physical cards as there was a hard drive switch for instance.

tried system-config-network-tui and removed the network card from there and saved

• this removed all the configuration from the eth* in the network-scripts
• reboot didn't solve this

had to get the mac address of the network cards 

• ip link show <device name> 

then create a new ifcfg-eth0 file with vim and enter the following:

DEVICE="eth0"HWADDR="**YOUR_MAC_ADDRESS**"NM_CONTROLLED="no"ONBOOT="yes"BOOTPROTO="dhcp"

then ifdown eth0 and ifup and it will read the new MAC and activate the card