Question

我正在尝试向C＃中的路由器发送ICMP AddressMask请求。但是，我的套接字总是超时，或者，如果未设置超时，则无限期地使应用程序循环。这是代码：

Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Raw, ProtocolType.Icmp);
socket.Bind(new IPEndPoint(interfaceAddress, 0));

Random rnd = new Random();
UInt16 seed, sn;

seed = (UInt16)rnd.Next();
sn = (UInt16)rnd.Next();

var icmpAddressMaskRequest = new Byte[12];

icmpAddressMaskRequest[0] = 17;
icmpAddressMaskRequest[4] = (Byte)(seed >> 8);
icmpAddressMaskRequest[5] = (Byte)(seed & 0xff);
icmpAddressMaskRequest[6] = (Byte)(sn >> 8);
icmpAddressMaskRequest[7] = (Byte)(sn & 0xff);

UInt16 checksum = 0;
for (int i = 0; i < 6; i++)
{
    Int32 twoOctects = icmpAddressMaskRequest[2 * i] * 256 + icmpAddressMaskRequest[2 * i + 1];
    Int32 tempChecksum = checksum + twoOctects;

    if (tempChecksum > UInt16.MaxValue)
        checksum = (UInt16)((tempChecksum & 0xffff) + 1);
    else
        checksum = (UInt16)tempChecksum;
}

icmpAddressMaskRequest[2] = (Byte)(255 - checksum >> 8);
icmpAddressMaskRequest[3] = (Byte)(255 - checksum & 0xff);

EndPoint remoteEndPoint = new IPEndPoint(IPAddress.Parse("192.168.100.1"), 0);

socket.ReceiveTimeout = 2000;
socket.SendTo(icmpAddressMaskRequest, remoteEndPoint);

var buffer = new Byte[4096];
socket.ReceiveFrom(buffer, ref remoteEndPoint);

我知道很多类型的路由器都没有响应地址掩码请求，但我尝试使用简单的Echo-Request，结果是一样的。

Answer 1

您应该从下载Wireshark开始，这将允许您查看是否实际发送了响应（以及您的请求是否正在发送）。

关于ping没有响应的事实，其他人有the same problem。

这段代码可能会遇到C＃处理按位操作的问题，你必须非常小心，因为Byte总是被签名并经常升级为int，这会导致各种意外结果。< / p>

ICMP套接字总是超时

1 个答案: