[K12OSN] terminal was working, now stalls when loading kernel

[Petre Scheie]

I've got a 4.0.1 (FC1) k12ltsp server that has just a single thin client.  The 
client was booting just fine.  But the server was having trouble printing to the 
USB printer attached to it.  So, among other things, I rebooted the server at 
one point, and while I don't think that was the actual fix, I was able to get 
printing to work.  Then I went back to the client machine, hit the reset button. 
  It boots from an etherboot floppy.  It gets an IP address from the server, but 
when it starts to load the kernel it seems to stall, displaying just a few dots 
at a snail's pace (I gave up after 20 minutes).  I suspect the firewall 
(iptables) is interfering, as I think I turned it off originally, though not 
permanently, to get things working.  Has anyone seen this before?  I used just a 
standard install, no firewall tweaking.  What ports need to be open for clients 
to load the kernel?

Petre