You have to have IP Aliasing compiled into the kernel. Use the ifconfig
command:
/sbin/ifconfig eth0:0 x.x.x.x netmask 255.255.x.x up
Use the second IP Address instead of x.x.x.x and put the correct information
in for the subnet mask. I have this command in my rc.local file so that it
executes upon bootup. I am sure there is a better way, but that is all I
knew to do.