If I dont't login to love0day@warchall to execute the curl command, I can't control my local port even if 4200.
But I can control my port to 4200 when I execute the command after ssh to love0day@warchall.So It must be the casue of ISP.
I don't know why it must be 42. There is some difference between them? I know use what parameter of curl,but the port number make me crazy.