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

$_GET problem
Hi all,

Have a bit of a problem with a little piece of code, I am not sure if this should be

serializing objects - loses methods - the point being?
Hi

I know that serializing an object will lose the methods. But whats the point in that? What

Delete all files in folder except with certain name
I have a script that I want to delete all files in a folder (taken from a database) except for one n

I got my hosting suspended XD
So I saw this challenge a day or so ago

http://www.programming-challenges.com/pg.php?page=dow

Count number of records in all the tables with a querry URGENT PLEASE...
I downloaded ORACLE 9I DATA DUMP into my comp. There are number of tables. I need to find out the

Email to a friend script problems
I have this send-to-a-friend script with 2 issues:


1) When you open the form popup on a p

Reading Most Recent CSV File in Directory
I thought I had wrapped this project up, but found out that the program I use to FTP a csv file to m

Certain files upload, while others do not
I want to read the data from an uploaded file. Not sure why, but it only uploads for certain files.

login to other site by sending post variables
hey,

here is my problem: my school gave me a mail account for school-stuff use. they mail us

how to export excel file in same server
My first post - php newbie, so appreciate your support.

I'm currently using headers to save w