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

PHP url branch??
Functionally, using PHP, I'm doing a test of login input submitted by a user via an html form in a f

asp authentication problem
Hello all, I want to use the asp authentication (from asp.net configuration) in my web site. there

This is driving me nuts!
This insert query looks to be alright, however I get this error:

QuoteYou have an error in yo

what does this mean? +=
is anyone able to explain what this code is saying?

i had it written for me awhile back and n

Keeping data in form
How can I keep whatever I write in the form?

Help Import Animoto and Youtube
CAn someone help me urgently want to allow users on my website to import youtube/revver/dailymotion

How can I Compare two xml documents?
Hi all,

I am doing a POC for my project and I am using XE database 10g version.

Strange cookie problem. setcookie dependant on where user was directed from?
Hello,

I have a website that sets a cookie when a user visits the website. The cookie holds a

Internal Server Error issues
This has been bothering me for weeks and I've been trying to solve it without asking for help, but e

Taking an HTML form and a PHP program and making it into one working file.
Hello,

So I would like to display everything INSIDE a specific directory. In other words, I