Have you taken a look at the FOG Server to ensure firewalls are disabled?
In Ubuntu is verified with:
[code]sudo service ufw disable[/code]
In CentOS you need to ALSO disable selinux:
[code]chkconfig iptables off
service iptables stop
sed -i ‘s/SELINUX=enforcing/SELINUX=disabled/’ /etc/sysconfig/selinux
sed -i ‘s/SELINUX=enforcing/SELINUX=disabled/’ /etc/selinux/config
reboot[/code]
Have you verified that the permissions of the /tftpboot directory are correct? They should be set to:
[code]chown -R fog:root /tftpboot[/code]