WSAEISCONN - Error 10056

Question/Problem: Socket is already connected.

Answer/Solution: A connect request was made on an already connected socket; or, a sendto or sendmsg() request on a connected socket specified a destination when already connected.

Winsock description: Winsock doesn't support the sendmsg() function, and some Winsock implementations are not so strict as to require an application with a datagram socket to "disconnect"--by calling connect with a AF_INET NULL destination address: INADDR_ANY (0.0.0.0), and port 0--before redirecting datagrams with sendto or connect. On a datastream socket, some applications use this error with a non-blocking socket calling connect to detect when a connection attempt has completed, although this is not recommended since some Winsocks fail with WSAEINVAL on subsequent connect calls.