[K12OSN] Problem getting Workstations to Boot

[Ken Grant]

Hi All:

I'm have a very frustrating problem that I need some help on.

I've installed K12LTSP 4.2 on a Dell PowerEdge 2850 server.  The server
has two SCSI drives, two Xeon processors, 6 gigabit ethernet cards, etc.
My network has a D-Link router and 3Com SuperStack 3900 swithches.  The
router is connected to the same switch as the workstations.

What is happening is this: When I try and boot a client, either with a
boot floppy, bootable NIC, or PXE I am unable to load a kernel.  Actually,
I can sometimes load a kernel and other times not.  It is very
inconsistent.  All workstations always pull an IP address but then stop.

I've tried eliminating the switch and just have a workstation go through a
hub and have had some success with this.  But tomorrow that workstation
may not boot using the hub.  I've read the docs at ltsp.org and they have
been very helpful.  It appears that k12 is configured correctly; however,
from the behavior of the workstations I'm not sure.

Some of the information I have found on the net indicates I should not
have the router on the same switch as the workstations, is this correct?
Since this is an on-again off-again thing, could the gigabit NICs be the
problem?  It almost appears that something is timing out.  Could this be a
problem with UDP?

Any help on this you can provide would be very helpful.

Cheers,
Ken