A existing connection was forcibly closed by the remote host. Destination address required. A required address was omitted from an operation on a socket. The system detected an invalid pointer address in attempting to use a pointer argument of a call. This error occurs if an application passes an invalid pointer value, or if the length of the buffer is too small.
Host is down.
A socket operation failed because the destination host was down. A socket operation encountered a dead host. Networking activity on the local host has not been initiated. No route to host. A socket operation was attempted to an unreachable host.