we have strange situation with our client-server platform. On filed we have 10 clients with same firmware version but on different networks. Client sends 50 bytes of payload to server every 15sec. Clients are connected behind NAT and everything works perfectly fine except for one client. TcpVIew software shows that particular client as in SNY_RCVD state.
After 1-3 days we got into trouble because client is unable to reconnect with server. On server we have WCF service, basic TCP listener. The thing is that client doesn't even reach our server software because it is unable to connect with OS socket layer (windows Server 2012).
We applied "Hardening TCP Stack" guidelines from MS but it doesn't help. We tried to restart Server several times - it doesn't help.
Here is wireshark capture and if anyone can figure out what's happening or even give us some direction...
Thank you.
wireshark capture
TcpView
0 Answers