If you ever programmed networking applications then you should know that it is impossible to control the timeout for blocking sockets on calling connect() function. This timeout is controlled by the operating system and may last up to 45 seconds when you want to connect to a non-existing host. Since blocking sockets are very attractive due to their simplicity in usage comparing to non-blocking (asynchronous) sockets, such a limitation disappoints many developers. You can change the value of timeout globally for the system, but I would like to warn you to avoid making any changes of the operating systems, as these changes will affect ALL networking applications running on your computer. In most cases, such a behavior is not desired.

In order to solve this problem you can use the following trick.

You can temporarily change the mode of the socket from blocking to non-blocking. Then connect to the target host using connect() function. If the return value is WSAEWOULDBLOCK, then just wait for the specified time using select() function checking the socket for writability.

Here is the code of the connectex() function, which you can use instead of the regular connect().

// Method:     connectex
// Description: Connect with timeout for blocking sockets 
// Parameter:  SOCKET s - socket handle
// Parameter:  const struct sockaddr * name - socket address structure
// Parameter:  int namelen - length of the socket address structure
// Parameter:  long timeout - timeout value in milliseconds
// Returns:    int : 0 - success, SOCKET_ERROR - error
int connectex(SOCKET s, const struct sockaddr *name, 
                        int namelen, long timeout) 
    // As connect() but with timeout setting. 
    int            rc = 0; 
    ULONG          ulB; 
    struct timeval Time; 
    fd_set         FdSet; 

    ulB = TRUE; // Set socket to non-blocking mode 
    ioctlsocket(s, FIONBIO, &ulB); 

    if (connect(s, name, sizeof(SOCKADDR)) == SOCKET_ERROR) { 
        if (WSAGetLastError() == WSAEWOULDBLOCK) { 
            // now wait for the specified time 
            FD_SET(s, &FdSet); 

            Time.tv_sec  = timeout / 1000L; 
            Time.tv_usec = (timeout % 1000) * 1000; 
            rc = select(0, NULL, &FdSet, NULL, &Time); 

    ulB = FALSE; // Restore socket to blocking mode 
    ioctlsocket(s, FIONBIO, &ulB); 

    return (rc > 0) ? 0 : SOCKET_ERROR; 

This code is not mine. I personally, modified it for my own needs.