So you've decided to add another nic to openfiler 2.3

here is the easy way (unless it auto detects, cause that's easier)

Go into /etc/modprobe.conf

Setup the eth2,3,4, whatever just like eth0,1 whatever

go into /etc/sysconfig/network-scripts

cp ifcfg-eth1 ifcfg-eth2(new interface)

open it, modify the following lines
DEVICE=eth2
and
IPADDR=192.168.10.10
so you don't have conflicts

save it, reboot, you should now see it in your UI