W5500 TCP listen problem, can't connect after some time

Hi. I have problem with W5500 module. I have configured four sockets to listen, all on the same port 502. In general everything seems fine. I can connect to wiznet device. But… I did some long term tests and after a while I am unable to connect to wiznet module. To do test I used PacketSender software on my PC. I configured software to use four connections, which try to connect to wiznet every 0.1 seconds, send one frame of 11 bytes, than disconnect. At first communication is ok, but after several minutes to few hours software can’t connect to wiznet module anymore. All four wiznet sockets are in SOCK_LISTEN state. I observe this behaviour in both static and dynamic IP configuration. I use ioLibrary to configure wiznet module. Reseting wiznet module helps, but then after some time situation repeats.

Here is log from Wireshark when wiznet is inaccesible:
4 3.091835 IntelCor_c6:4e:5b Broadcast ARP 42 Who has Tell
5 3.105887 RigolTec_35:f5:b6 00:00:00_00:00:00 PPP LCP 60 Echo Request

RigolTec_35:f5:b6 is a wiznet W5500 module and sends infinitly PPP LCP 60 Echo Request every second.

I will be very gratefull for any tips on this one. Thank You.

When this situation happens, perform full dump of all the registers - common and sockets’. Also capture extended Wireshark log just before and for some time after this happens.