无法接收 UDP 数据包

Question

我正在尝试使用两个单独的程序从同一台机器发送和接收 UDP 数据包，但到目前为止我还没有收到任何东西。我已经尝试完全关闭我的防火墙，但仍然没有用。

发送节目

var sender = new UdpClient(Dns.GetHostName(), 2055);

var data = new byte[] { 0, 1, 2, 3, 4, 5 };
sender.Send(data, data.Length);

接收节目

var receiver = new UdpClient(2055);

var endPoint = new IPEndPoint(IPAddress.Any, 2055);
var data = receiver.Receive(ref endPoint);
System.Console.WriteLine("Data received");

我什至复制并粘贴了本教程中的代码http://www.codeproject.com/Articles/10649/An-Introduction-to-Socket-Programming-in-NET-using，但仍然没有成功。

Answer 1

来自About multicast IP addresses and ports (TechNet)：

Multicast IP addresses are class-D addresses that fall within two ranges: 224.0.0.0 through 239.255.255.255 and FF00:0000:0000:0000:0000:0000:0000:0000 through FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF. The addresses in the first range are Internet Protocol version 4 (IPv4) addresses. The addresses in the second range are Internet Protocol version 6 (IPv6) addresses.

For intranet use, it is recommended that you use IPv4 addresses in the range 239...*. Port numbers can range between 1 and 65535. The routers on the network over which you are transmitting your content must be multicast-enabled, meaning that they must be able to interpret class-D addresses or they will not be able to forward your multicast information to clients.

由于网络级过滤，您必须使用此范围内的 IP 地址。维基百科上有 table 个 commonly-used multicast addresses。

实际上，您使用的教程也注意到了这一点：

UDP also supports multicasting i.e. sending a single datagram to multiple receivers. To do so, the sender sends a packet to an IP address in the range 224.0.0.1 – 239.255.255.255 (Class D address group).

Answer 2

问题出在var sender = new UdpClient(Dns.GetHostName(), 2055);

您需要指定您的本地主机 IP，即 127.0.0.1，因为您在同一台机器上。这应该有效：

var sender = new UdpClient("127.0.0.1", 2055);

无法接收 UDP 数据包

Unable to receive UDP packets

.net

c#

networking

udp