How to close socket (TCP) completely?

Question

C++ / C#

After the call

shutdown(tcp->sockfd, SHUT_RDWR);
close(tcp->sockfd);

the socket remains in the FIN_WAIT2 state for a long time (I look in TcpView)
Is it possible to close it completely?

Answer 1

Set the setsockopt() option to SO_LINGER with a zero or small timeout before closing the socket.

Answer 2

Do so