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

PHP5 - Verifying a secure mail is secure
I need to send an e-mail from a form to a external department and because it contains personal custo

Image upload - determine folder
I have an upload script that may be accessed from different directories. Problem is, the script is m

MII Netweaver Server stopped due to CPIC connection Problem
Dear Experts,
We have SAP XMII 12.0 setup running on Netweaver 2004s,7.0, Java Stack only.

Passing PHP variables from one page to another
Hello-

I'm having trouble figuring out how to transport a variable from one php file to anoth

PHP mail() returns true but doesn't work
First off I apologize if this is a newbie question, and I generally don't like asking questions that

phpmailer class & pop.gmail.com?
Code: <?php
$mail->IsSMTP();
$mail->Host = "pop.gmail.com";

recrawling
Can anyone suggest me how may i know a page is updated before it is being downloaded, so that i can

IIS on 2003 anon access disabled issue
I have an IIS server that belongs to a domain, and anonymous access is turned off for all my sites.

Web Host List
Here is a list of web hosts that offer PHP and MySQL. It is no where near a full list, but it is mos

login page does not execute a else statement
I've created a login page using sessions.
When an incorrect user name or password is entered then