Binding 2 UDP sockets on same port, connected to different destinations, 1 receives

Posted on 16th Feb 2014 07:03 pm by admin

Hello,
My application wants to send/recv data to 2 different UDP ports on a remote computer, using the same source port.
So I bind to the same local port which works, and connect to the remote IP : port which works as well, but then randomly only one of the two sockets will receive data from the stack, even though packets are arriving on the network for both.

In this code, the local UDP port is always 13398; the first time this code is called, the destination is 192.168.13.45:6970 and the second time it's 192.168.13.45:6972.
What would cause only one of the sockets to receive data afterwards? Also it's randomly the first or the second one that receive data, but once both sockets are binded and connected, only that random one will receive data.

Thanks!

SOCKET serverSock = ::socket(AF_INET, SOCK_DGRAM,IPPROTO_UDP);
int i=1;
if ( setsockopt(serverSock, SOL_SOCKET, SO_REUSEADDR, (char *)&i, sizeof(i)) != 0 ) {
logger.warn(_T("Could not set SO_REUSEADDR: %s"), GetWSATextError(WSAGetLastError()));
}

SOCKADDR_IN saServer, dest;
memset(&saServer,0,sizeof(saServer));
saServer.sin_family = AF_INET;
saServer.sin_addr.s_addr = INADDR_ANY; // Since this is a server, any address will do
saServer.sin_port = htons(m_manager->GetLocalUDPPort()); // Convert int to a value for the port field
int ret = bind(serverSock, (struct sockaddr *) &saServer, sizeof(saServer));
if (ret != 0) {
logger.warn(_T("Could not bind to udp port 1: %d, %s"), m_manager->GetLocalUDPPort(), GetWSATextError(WSAGetLastError()));
return false;
}

memset(&dest,0,sizeof(dest));
dest.sin_family=AF_INET;
dest.sin_addr.s_addr=m_deviceIP;
dest.sin_port = htons(m_devicePort1);
ret = connect(serverSock, (sockaddr *) &dest, sizeof(dest));
if (ret != 0) {
logger.warn(_T("Failed to connect to udp 1: %s:%d, %s"), inet_ntoa(dest.sin_addr), m_devicePort1, GetWSATextError(WSAGetLastError()));
return false;
}

Your Answer:

Login to answer

Other forums

Problems with returning true or false in eval()'d code
Hi guys,

Would appreciate some help with a problem when running eval() on a function that sho

Disable Scrollbar in TableControl
Hello everbody,

please can anybody help me - outherwise i'm going to become desperate :P<

IIS & NW MII on the same server
Hi,

We're weighing the possibility to run both IIS and MII (NetWeaver) on the same server

quick question
Hi ..

i have a question
how do i set a var so it displays via an echo
Code: $logo = '&a

Career Change into SAP
Hai
I am sajesh ,did my diploma in Mechatronics i have a 4 years of experience in

Fetching array then reversing it
Hi, I have a simple problem, I'll try to explain it as best I can:
News entries in my database ar

CRM?
I think that's what they're called. Customer Management System? Anyway. Is there any good free ones

WELCOME SCREEN
first of all let me tell you what does my script do,

it´s a very simple query to show a e

form variables from database help.
Hi all,

I would like to have a form that gives you options based on the results of an mysql q

HTML Email rec'd as Source Code
The code does create and send the email successfully. However, the message shows as html code and n