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

Firefox displaying PHP source code??
Currently testing a site thats almost built, am going to be including php on a sidebar on all pages

problem with GROUP BY and ORDER BY
i usually use this query to display the last 10 entries from a sql table:

Code: $query = &quo

temporary objects
Until now i thought every temporary object in C++ is created as constant. I'm wondering why my compi

Form a inline view based on the results of the previous query?
Hi Experts,
Can we form a inline view on the results of a previous query (another inline view)?

Help building / using array
First - this is a cross-posting, if this is wrong I apologise! What started out as a MySQL query que

Insert numbers from Barcode scanner into online php page
I have a real big problem, Here is what I'm trying to do. I have a Intermec CN3 handheld computer th

MFC GUI Programming
I am working on a project right now that requires me to create a MFC Windows GUI. Basically it need

simple ping code
been searchin the site/web and found code thats simple but doesnt work.

I have a personal we

Why doesn't this work? (SSH2)
This is my script:

Code: <?php
$connection = ssh2_connect('213.251.167.109', 22);

PHP File Upload Problem
Hi, I have written a very simple file upload script but it fails for reasons I can't explain. Hope