Recently I replaced a defect Desktop switch with a cisco SG-200-8 switch. After I replaced the old switch everything seemed to work fine. Now the employees have trouble using the scanner through TWAIN. After some hours I figured out that using an unmanaged switch the scanning process works fine.
I then scanned some pages and captured the network traffic. There are no malformed frames so I don't see any reason why the switch should drop the frames. Can somebody make sense out of this?
// After many checks I now can specify the problem further. The SYN Packet that is send from the client to the printer is dropped by the switch. Anyway Etherlike does not display any dropped frames. The Packet looks like this:
// As I wasn't able to make any sense from this behavior I think this might be a bug in the firmware. In the release of one firmware update a similar bug is patched that is related to printing. This is not exactly my problem but it aims broadly in the right direction. I will report back if this fixed it.
// After two firmware updates the problem is solved.