Last week I upgraded several Netware 6.5 SP5 servers to Netware 6.5 SP6. After a few days all the servers were operating normally except one, which runs several of the Zenworks 7 SP1 Desktop management modules: Imaging, Wake on LAN (WoL), Workstation Import and Removal.
The first symptom reported was nobody could image workstations. When the workstations booted up, they received the following errors:
PXE-T04: Illegal TFTP operation
PXE-E36: Error received from TFTP server
PXE-M0F: Exiting Intel Boot Agent
No errors were visible on the server’s console, and all the Zenworks modules appeared to be functioning properly.
I found on Novell’s NW65SP6 wiki that this is a known issue and is fixed by applying the latest Winsock patch, which is currently 6.23.02 (wsock6l.zip). The problem is that UDP ports are being opened on the imaging server but not closed when they are not in use. Once 4999 UDP ports are open on the server, TFTP stops working. Rebooting the server will temporarily solve the problem, until the number of open UDP ports exceeds 4999 again.
TID 3917344 reports a similar problem with NW65SP5 where imaging stops working on a random basis, and the fix for this issue is also to apply the latest Winsock patch. The patches are available for Netware 5.1 SP8, 6.0 SP5, and 6.5 SP5/SP6.
TID 3296492 reports this problem can also be caused by outdated Broadcom network card drivers.