At work I have a bunch of devices that communicate to and from a computer using raw 802.3 ethernet. Communication to the devices is mediated by a little program a coworker wrote, which uses the winPcap library to generate the ethernet packets.
The network topology is simple: an ethernet cable connects one NIC on the computer to an ethernet switch, and several of my devices attach to the various sockets on the switch. Everything was working fine, but then I had to reformat the computer and now I cannot communicate with my devices.
If I connect the NIC directly to one of the devices, it works fine. When I try to go through the switch, it seems that the devices do not receive packets sent out from the computer.
This is a D-Link switch with no user accessible settings as far as I can tell. Could this be an issue with NIC settings? Is there some way to reset the switch?