Each device on my network has a fixed static ip, therefore multiple devices using the same ip is not a problem. Of course it is always possible that there is a hardware problem either with the device or with the connector, but there may be other reasons - and I want to find out the real reason for the problem, not just guess. If it is possible to understand the root of the problem, it will save a lot of work. I hoped that maybe somebody may be familiar with the exact cause of the problem - this is actually the reason for the logs: maybe a particular line there may provide enough clue.