我有一个 VPN 客户端，它可以很好地通过 VPN 管道发送单播 UDP 数据包，但不能对多播 IP (UDP) 数据包 (OpenVPN) 执行此操作。所以我想我可以写这个小垫片，它将采用 IP(端口 3000)多播并将它们作为单播通过 VPN 发送。
我看到多播数据包到达，但我没有看到 VPN 端有任何到达(WireShark 没有帮助，因为与 IpConfig/all 不同)它没有看到 VPN 接口(interface)。)。
我想我的问题可能是我不太清楚 BIND 和 CONNECT 之间的区别，以及我应该将 UDPClient 绑定(bind)到哪个接口(interface)(vpn 或本地)。
命令行是:
239.0.0.0 198.168.0.15 10.4.30.239 172.27.225.77
arg[0] = multicast from address
arg[1] = unicast to address
arg[2] = local physical ethernet assigned address
arg[3] = virtual address of computer on VPN network (client)
using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Sockets;
using System.Threading.Tasks;
namespace MUTunnel
{
public class EchoBot
{
protected UdpClient sender;
protected UdpClient listener;
protected const int listenPort = 3000;
protected const int outPort = 3000;
protected IPEndPoint inPoint;
protected IPEndPoint outPoint;
protected IPAddress listenAddress;
protected IPAddress sendAddress;
protected IPAddress localAddress;
protected IPAddress vpnAddress;
public EchoBot(string from, string to, string local, string vpn)
{
bool parsed = IPAddress.TryParse(from, out listenAddress);
parsed = IPAddress.TryParse(to, out sendAddress) && parsed;
parsed = IPAddress.TryParse(local, out localAddress) && parsed;
parsed = IPAddress.TryParse(vpn, out vpnAddress) && parsed;
if (!parsed)
{
System.Console.WriteLine("Usage: MUTunnel <source multicast IP> <dest unicast IP> <local host IP address> <vpn IP address>");
Environment.Exit(1);
}
listener = new UdpClient();
listener.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
inPoint = new IPEndPoint(localAddress, listenPort);
listener.Client.Bind(inPoint);
listener.JoinMulticastGroup(listenAddress);
sender = new UdpClient();
sender.Ttl = 64;
sender.AllowNatTraversal(true);
//outPoint = new IPEndPoint(sendAddress, outPort);
sender.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
sender.Connect(sendAddress, outPort);
}
public void send(byte[] bytes)
{
sender.Send(bytes, bytes.Length);
}
public void loop()
{
bool done = false;
try
{
while (!done)
{
byte[] bytes = listener.Receive(ref inPoint);
Console.WriteLine("Received Multicast from {0} : length {1}\n", listenAddress.ToString(), bytes.Length);
this.send(bytes);
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
finally
{
listener.Close();
sender.Close();
}
}
}
class Program
{
static void Main(string[] args)
{
if (args.Length != 4)
{
System.Console.WriteLine("Usage: MUTunnel <source multicast IP> <dest unicast IP> <local host IP address> <vpn IP address>");
Environment.Exit(1);
}
EchoBot echoBot = new EchoBot(args[0], args[1], args[2], args[3]);
Console.WriteLine("MUTunnel Waiting for messsages...");
echoBot.loop();
}
}
}
ipconfig/all 内容如下(OpenVPN 客户端运行时)
P:\>ipconfig /all
Windows IP Configuration
Host Name . . . . . . . . . . . . : YSG4206
Primary Dns Suffix . . . . . . . : draper.com
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : draper.com
Ethernet adapter Ethernet 3:
Connection-specific DNS Suffix . : draper.com
Description . . . . . . . . . . . : Killer E2200 Gigabit Ethernet Controller
Physical Address. . . . . . . . . : F8-B1-56-FF-8B-36
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IPv4 Address. . . . . . . . . . . : 10.4.30.239(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.254.0
Lease Obtained. . . . . . . . . . : Monday, June 18, 2018 5:28:03 PM
Lease Expires . . . . . . . . . . : Thursday, June 21, 2018 8:46:50 PM
Default Gateway . . . . . . . . . : 10.4.31.254
DHCP Server . . . . . . . . . . . : 140.102.100.111
DNS Servers . . . . . . . . . . . : 10.10.20.11
10.10.20.12
NetBIOS over Tcpip. . . . . . . . : Enabled
Ethernet adapter Ethernet:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : TAP Adapter OAS NDIS 6.0
Physical Address. . . . . . . . . : 00-FF-91-E7-8A-38
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv4 Address. . . . . . . . . . . : 172.27.225.77(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . :
NetBIOS over Tcpip. . . . . . . . : Enabled
P:\>
更新
已添加 发件人.Ttl = 64; sender.AllowNatTraversal(true); 还在选择了 VPN 接口(interface)的客户端上运行 RawCap。数据包转储没有显示我正在转换为单播并尝试发送到进入该接口(interface)的 129.168.0.15 的多播数据包。
只是一些其他的东西。 (请参阅来自 RawCap 的 .pccap 文件的 wireshark 显示。
最佳答案
我怀疑你没有监听单播的另一端。
Unicast is the term used to describe communication where a piece of information is sent from one point to another point. In this case there is just one sender, and one receiver.
我添加了一个额外的监听器来监听发送端点，一切正常并将打印出已发送的消息。
在ip为:198.168.0.15的电脑上运行附加监听
IPAddress localAddress = IPAddress.Parse("198.168.0.15");
const int listenPort = 3000;
var listener = new UdpClient();
listener.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
var inPoint = new IPEndPoint(localAddress, listenPort);
listener.Client.Bind(inPoint);
while (true)
{
byte[] bytes = listener.Receive(ref inPoint);
Console.WriteLine("Received Message from {0} : message {1}\n", localAddress.ToString(),Encoding.ASCII.GetString(bytes));
Thread.Sleep(1000);
}
关于C# UDP 客户端读取组播 IP(本地接口(interface))，并将单播 UDP 发送到 VPN，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/50801239/