Netboot/SUS: tftp not working, giving a timeout error

[fuzzycheck]

Hi, I installed the Netboot/SUS appliance in VirtualBox. The iMacs on my network see the Faux Netboot when I boot them, but the net boot fails with a kernel panic. I tested a tftp connection from an iMac as a troubleshooting step, and it doesn't seem to work.

$ tftp myserver
tftp> get /DSR.nbi/NBImageInfo.plist
Transfer timed out.

I had the same error with the tftp server on a Centos machine and it was resolved after disabling SELinux and the firewall. Is there a firewall on this appliance?

Note: I've changed the permissions on the folder because they should belong to smbuser after following the user guide:
chown -R smbuser.root /srv/NetBoot/NetBootSP0/
ls -l /srv/NetBoot/NetBootSP0/DSR.nbi/NBImageInfo.plist

But tftp seems to use "tftp" instead
ps -ef |grep tftp
root 909 1 0 08:29 ? 00:00:00 /usr/sbin/in.tftpd --listen --user tftp --address 0.0.0.0:69 --secure /srv/NetBoot/NetBootSP0

I already tried changing the permissiong with the same error:
chown -R tftp /srv/NetBoot/NetBootSP0/

Thanks for your help.

[fuzzycheck]

I found the problem: it was a firewall on the iMac from which I was getting to the reboot/sus.

Also I have changed the permissions to:
chown -R smbuser.tftp /srv/NetBoot/NetBootSP0/