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

ok i need to join all this pages to make 1 neat code
i have 5 pages that make up my tv guide it works 100% but i want to make it 1 page if i can or 2, i

PHP Form to Variable.
Hi! I have written a HTML-form code in DreamWeaver CS3 (in a PHP doc) and I really need it to work s

Get ID from Database when Posting with a HTML Form
I have a form I am submitting to a MySql database. Each product has an ID # attached to it that auto

Embedding flash object in Else statement
This is my first major project in PHP and I'm having some trouble embedding a flash object in an Els

Form Help
Here is the form:

Line number On/Off | Expand/Contract<? include("../include/sess

Change image filetype on upload?
Hi,
I've got a form which uploads an image to the server.
Is it possible to change the image t

ImageCreate()
When I create an image and add text to it I want my text to be replaced with a PNG image, because th

Backflush
I am looking for a report in SAP that would give me a list of all parts that are populated with a ba

PHP page loading in Firefox but not in IE
hello,

i am currently doing a project in PHP and i have a problem. If I view the project in M

New Search Engine
Hey everyone,

I have a ZIP Code Radius search engine already functional. it displays all of t