在侦听器中，我认为您需要设置

In the listener, I think you need to set

listeningMc_req.imr_interface.s_addr = htonl(INADDR_ANY);

...，因为这也是绑定套接字的接口.根据您是否在单个主机上运行所有内容，您可能需要考虑回送接口，并绑定到INADDR_ANY即可做到这一点.

... since that is also the interface on which you bind the socket. Depending on whether you run everything on a single host, you might need to consider the loopback interface and binding to INADDR_ANY will do that.