The way I've done it before is as follows (assuming you are adding an alias to eth0, if it is a different interface just change it in the relevant places):
Copy the /etc/sysconfig/network-scripts/eth0 file to /etc/sysconfig/network-scripts/eth0:1
Edit /etc/sysconfig/network-scripts/eth0:1 by changing DEVICE=eth0 to DEVICE=eth0:1 and setting the other parameters (ie IP address etc) as appropriate.
Type: ifup eth0:1
To add more aliases just use eth0:2, eth0:3 etc
The only thing to watch out for is I once found a few things in the original eth0 file that had to be removed in the alias otherwise it annoyed it - I can't remember a specific example but I think it was something hardware specific.
I can't help you with APF because I don't know what that is.