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

PHP/Database issue
My friend is helping me make a database where you go to a certain webpage of my site and the page wi

selectbox+database connection retrive problem
Code: [Select]
<tr>
<th align="left" scope="c

Problem with HTML form
Hello,

I made a HTML form with some fields and check box.
Everything works fine except whe

list files from folder, only one for each date
I have many files in a folder and wish to only list one of each date

these are the file names

Need a fuction to count entries in a field
Hi
I need a fuction to count how many times a email address is entered in to a field.

I ma

New Login Script
Hi all, i attempted to create a whole new login script witch isnt working for some reason i dont kno

How to add functionality to a simple php calender?
Hello everyone,

I have just finished creating a simple php calander. Can someone point

PHP Thumbnail Creation
Ok so i use this function to create thumbnails:

Code: [Select]function createthumb($name,$fil

What are the two different files you download to update kernel?
What are the two different files you download to update kernel?

Captcha problem users just refresh and it will let them auto submit again
Users will just re submit and not have to enter the new captcha.. ? Lol but if i refresh the page, t