kNC or Texas Instruments
it can be difficult to time it just right, I had similar woes...
gotta scan at just the right time to catch it for me it was...
The moment you get the ip....
then turn dhcp off on the gui asap, and assign i.p.'s before cgminer closes the connection.
good luck.
P.S. during the green light flashing on ethernet. If it stops, start over.
if you can putty in... You will most likely find the workername on the mining page is wrong.
you can change it there instead, just be sure to save to /config/cgminer.conf and not the root address.
that will fix it.
i dont follow this but it sounds promising.
but... it may be easier to use putty and get in directly thru cgminer..., you can keep the connection live if you make it in... still change the info on the gui networking page