lc := &net.ListenConfig{
		Control: func(network, address string, c syscall.RawConn) error {
			c.Control(func(fdPtr uintptr) {
				if opts.Interface != "" {
					// When interface is specified look for specifically port availability on
					// the specified interface if any.
					_ = syscall.SetsockoptString(int(fdPtr), syscall.SOL_SOCKET, syscall.SO_BINDTODEVICE, opts.Interface)
				}
			})
			return nil
		},
	}