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

How to submit a form to the same page?
I have a table containing information about books in my library and this table has the following col

Php - mysql select?
hi, i have this code:

Code: <?php
session_start();
// dBase file
include &quo

how to remove in php string display
My code is $message="We're looking at developing our website."; $body= "My mess

Am I setting up my sites oldschool?
Ok,

When I create a site I open a basic template that I have created that consists of a css f

CHECK A STRING FOR ' " ' (DOUBLE QUOTES)
I am checking for delimiter (.!?) and if there is a " after a sentence then it should neglect a

SCO Unix
I know this might not be the place to ask, but, can anyone tell me if SCO Unix comes with PHP built

Query output more than expected
$query=mysql_query("SELECT * FROM players, communities, divisions WHERE dob BETWEEN '{$start_da

updating a single value to multiple non consecutive rows
I need to update the same value to multiple non consecutive rows. I need to add an experation date t

Users and Groups with PHP Classes
Hi,

I have setup what I hope to be a good working User class. Now I want to introduce group m

Writing Windows Device Drivers with C
Yes: one of the nice features of C is void*. You can put anything there and get anything out. Very