将UDP消息广播到所有可用的网卡

Question

我需要向特定的IP和端口发送UDP消息.

由于有3张网卡,

10.1.x.x
10.2.x.x
10.4.x.x

当我发送UDP消息时,我只在一个网络适配器中收到消息...其余的ip没有收到.

我想在发送消息时检查网络适配器.我怎样才能做到这一点？

---

目前我正在使用以下内容:

IPEndPoint localEndPoint = new IPEndPoint(IPAddress.Parse(LocalIP), 0);
IPEndPoint targetEndPoint = new IPEndPoint(TargetIP, iTargetPort);
UdpClient sendUdpClient = new UdpClient(localEndPoint);
int numBytesSent = sendUdpClient.Send(CombineHeaderBody, CombineHeaderBody.Length, targetEndPoint);

Answer 1

这实际上比它听起来更棘手,因为如果你有多个接口,广播将不会总是出现在所有接口上.为了解决这个问题,我创建了这个类.

public class MyUdpClient : UdpClient
{
   public MyUdpClient() : base()
   {
      //Calls the protected Client property belonging to the UdpClient base class.
      Socket s = this.Client;
      //Uses the Socket returned by Client to set an option that is not available using UdpClient.
      s.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, 1);
      s.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.DontRoute, 1);
   }

   public MyUdpClient(IPEndPoint ipLocalEndPoint) : base(ipLocalEndPoint)
   {
      //Calls the protected Client property belonging to the UdpClient base class.
      Socket s = this.Client;
      //Uses the Socket returned by Client to set an option that is not available using UdpClient.
      s.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, 1);
      s.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.DontRoute, 1);
   }

}

然后通过广播发送UDP数据包,我使用类似下面的内容.我使用IPAddress.Broadcast和MyUdpClient,这是从您的代码不同.

IPEndPoint  localEndPoint  = new IPEndPoint(IPAddress.Parse(LocalIP), 0);
IPEndPoint  targetEndPoint = new IPEndPoint(IPAddress.Broadcast, iTargetPort);
MyUdpClient sendUdpClient  = new MyUdpClient(localEndPoint);
int numBytesSent = sendUdpClient.Send(CombineHeaderBody, CombineHeaderBody.Length, targetEndPoint);

此外,您应该注意,当您使用特定ipaddress而不是广播时,路由表仅将其发送到与该地址匹配的接口.

因此,在您的示例中,使用单播.您需要设置LocalIP要发送到的本地接口的IP.使用三个接口,您将拥有三个本地IP,您需要选择要使用的正确IP.

IPEndPoint  localEndPoint  = new IPEndPoint(IPAddress.Parse(LocalIP), 0);
IPEndPoint  targetEndPoint = new IPEndPoint(TargetIP, iTargetPort);
MyUdpClient sendUdpClient  = new MyUdpClient(localEndPoint);
int numBytesSent = sendUdpClient.Send(CombineHeaderBody, CombineHeaderBody.Length, targetEndPoint);

由于路由已关闭,您可能会在所有接口上看到它,但您需要针对单播情况对其进行测试.

如果您不关心发送IP或端口,可以使用以下代码.

IPEndPoint  targetEndPoint = new IPEndPoint(TargetIP, iTargetPort);
MyUdpClient sendUdpClient  = new MyUdpClient();
int numBytesSent = sendUdpClient.Send(CombineHeaderBody, CombineHeaderBody.Length, targetEndPoint);

或用于广播

IPEndPoint  targetEndPoint = new IPEndPoint(IPAddress.Broadcast, iTargetPort);
MyUdpClient sendUdpClient  = new MyUdpClient();
int numBytesSent = sendUdpClient.Send(CombineHeaderBody, CombineHeaderBody.Length, targetEndPoint);

问题IPAddress.Broadcast是他们不会通过任何网关.要解决此问题,您可以创建一个列表,IPAddresses然后循环并发送.此外,由于发送可能因您无法控制的网络问题而失败,因此您还应该有一个try/catch块.

ArrayList ip_addr_acq = new ArrayList();

ip_addr_acq.Add(IPAddress.Parse("10.1.1.1")); // add to list of address to send to

try
{
   foreach (IPAddress curAdd in ip_addr_acq) 
   {
       IPEndPoint  targetEndPoint = new IPEndPoint(curAdd , iTargetPort);
       MyUdpClient sendUdpClient  = new MyUdpClient();
       int numBytesSent = sendUdpClient.Send(CombineHeaderBody, CombineHeaderBody.Length, targetEndPoint);

       Thread.Sleep(40); //small delay between each message
    }
 }
 catch
 {
 // handle any exceptions
 }

编辑:请参阅上面的更改为具有多个接口的单播,还有问题尝试将数据包单播到可用网络.