Hi, i use MQX 4.2, CW 10.6 and frdmk64f.
in my application, i stay in select() function waiting activity on the socket. i created this stream socket and i connect it to a remote server that is always running. sometimes the select() function return a error unexpected: 0x1719. it is unexpected because the server is always running and it not send any closing request. the freedom board is connected on a router that is connected on the network where the server stay.
i read the documentation of RTCS. In the chapter of select() function i see that it is explained that this error is returned from select() when happens "Abort request (remote host sends RST or unexpected SYN to us)".
My question is: what is the cause of this error? what means "unexpected SYN to us"?
When you get this error code it means the stack has already closed the TCB (whatever reason). Most typical is RST received from connected peer, but it can also be a received SYN when a connection is already established.
As the TCB does not exists, your software has to closesocket(). It can also open a new connection to the server.