Well, is tftpd-hpa service running when you reboot the machine?

If so then the fix won’t help you. If the service is not starting there is a way to make the service wait until the machine is booted and then it starts the service.

Incase it is the later of the two, the resolve is:

Change the line
[code]
start on runlevel [2345][/code]
in /etc/init/tftpd-hpa.conf to

[code]
start on (local-filesystems and net-device-up IFACE!=lo)
[/code]
And it is not a fault of FOG, this is a known issue with Ubuntu 12.04, and 14.04

You could try re-installing the tftpd-hpa service and see if that solves the issue:

[code]
sudo apt-get remove --purge tftpd-hpa
sudo apt-get update
sudo apt-get install tftpd-hpa
[/code]