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

I apologise! It's a newbie to PHP feedback form problem!
Hi,

I am a total newbie to PHP. I am also a unemployed and need to get a job. So after 100% r

in php, link returns to the line
When I add a link in a php page, the link word returns to the line (as a
would do)

Examp

Memory Allocation
Hi folks,
see this ex:

int v=5;
v=v+10;

then what will do the compiler before th

Can't seem to capture a variable in a chained select
I'm *this* close to having a chained select running but for some reason it doesn't seem to be pickin

passing data from one page to another
hey guys
i have the follwoing code to get information from one page and place on another:

Deleting pointers froms vector?
Hi. I have a vector filled with pointers and I want to delete the pointers. I could do a loop and do

please help
HTML Code:

Code: <span id="ctl00"><span>

Product categories for registration
Dear all,

We are going live with the Supplier registered next week. At standard, the 'sel

php not working written for consumption of slots
1. Here is the function where i will be allowed to consume the slot booked by me.

2. Here i c

Error with Font and imagettfbbox
I keep getting an error that says "Warning: imagettfbbox() [function.imagettfbbox]: Could not f