I know this thread is a little stale by now but for the sake of posterity, I was having the same issue after rebooting my FOG server (running Ubuntu 12.04 64-bit). I found that issuing:
[CODE]sudo service tftpd-hpa stop
sudo service tftpd-hpa start[/CODE]
brought everything back to life
I also found that adding
[CODE]/bin/sleep 30 && /etc/init.d/tftpd-hpa restart[/CODE]
to rc.local didnāt help (in fact, I already had that in my rc.local), however
[CODE]/bin/sleep 30 && /etc/init.d/tftpd-hpa stop
/bin/sleep 30 && /etc/init.d/tftpd-hpa start[/CODE]
did help. Donāt know why restart didnāt (maybe my server is too quick and needs some more time before it tries to restart the service - [FONT=Consolas]/bin/sleep 60[/FONT] perhaps?)
For the record (and to help anyone who doesnāt really understand Linux very well), my /etc/rc.local file contents are as follows:
[CODE]#!/bin/sh -e
rc.local
This script is executed at the end of each multiuser runlevel.
Make sure that the script will āexit 0ā on success or any other
value on error.
In order to enable or disable this script just change the execution
bits.
By default this script does nothing.
/bin/sleep 30 && /etc/init.d/tftpd-hpa stop
/bin/sleep 30 && /etc/init.d/tftpd-hpa start
exit 0[/CODE]