c＃udpClient发送的数据包不存在路由器

Question

using the following code:

UdpClient Sender = new UdpClient();

        try
        {
            Sender.Send(Encoding.ASCII.GetBytes(msgOut), msgOut.Length, ip);
        }

i am trying to send back a reply to the previous request to the same ip/port. while working on the same computer, it would only work if i customize the values to localhost, as it would not even work when i state my own computer IP in the NAT.

2 facts about it:

1) Same ip/port values work perfectly fine on my c++ version of it. (even across the globe) with the next code:

sockaddr_in si_custom;
int s_custom;
//create socket
if ((s_custom = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == SOCKET_ERROR)
{
    //socket fail
    return false;
}

//setup address structure
memset((char *)&si_custom, 0, sizeof(si_custom));
si_custom.sin_family = AF_INET;
si_custom.sin_port = htons(stoi(port));
si_custom.sin_addr.S_un.S_addr = inet_addr(ip.c_str());
//send the message
if (sendto(s, msg.c_str(), msg.size(), 0, (struct sockaddr *) &si_custom, slen) == SOCKET_ERROR)
{
    closesocket(s_custom);
    return false;
}
closesocket(s_custom);
return true;

2) after enabling close to anything remotely relative in the firewall, my wireshark packet sniffer tells me that my packets DO leave my computer perfectly normal.

I'm trying to figure out, why would ac# udpClient class behave differently than my c++ Udp code in the sense that my router refuses to pass the first one and agrees to pass the latter one.

Thanks in advance.

Answer 1

用我自己的Ip：port初始化UdpClient Sender对象解决了问题

UdpClient Sender = new UdpClient( new IPEndPoint(MyIP,MyPort));