I'm a Cisco instructor and many of the routers in my class give a:
%Error opening tftp://255.255.255.255/network-confg (Timed out)
messsage every time the students boot up with no config file. Sometimes "network-confg" is "cisconet-cfg".
As soon as the students create a config file it stops happening on reboot, but they write-erase and boot frequently during class and it's a real problem. I've tried "no service config" but that doesn't seem to help. And CTRL-SHIFT-6-x doesn't interrupt it; they just have to sit there for several minutes until it times out.
Any ideas how to shut this behavior off permanently?