Ok so here is the result, I got it working thanks to a person on this forum named aaoyagi.
When I followed his instructions my Linux distros booted without fail via my fog server over the network!!!
In case anybody wants the steps:
First in your /etc/exports add this line:
/var/www/fog/iso/15.04_64 *(ro,sync,no_wdelay,insecure_locks,no_root_squash,insecure)
Then restart your nfs server. If you’re running Ubuntu it’s sudo service nfs-kernel-server restart
Next, extract the Ubuntu iso to a direcotry named 15.04_64 in your /var/www/fog/iso directory.
In your Advanced menu use this:
:MENU
menu
item --gap – ---------------- iPXE boot menu ----------------
item ubuntu15.04_64 Boot Ubuntu 15.04
item return return to previous menu
:ubuntu15.04_64
set path /fog/iso/15.04_64
set nfs_path /var/www/fog/ISO/15.04_64
kernel http://${fog-ip}${path}/casper/vmlinuz.efi || read void
initrd http://${fog-ip}${path}/casper/initrd.lz || read void
imgargs vmlinuz.efi root=/dev/nfs boot=casper netboot=nfs nfsroot=${fog-ip}:${nfs_path} ip=dhcp splash quiet – || read void
boot || read void
goto start
Hopefully it works for you too. You don’t have to set the variables. I just did it that way in case I ever have to change where the iso directory lives.