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

IMAGE - SERVER SIDE scripting help...
How to receive pixel data of an image and buid a bitmap file on the server using the HTTP POST metho

phpMailer will not connect using SMTP
I am trying to use phpMailer with smtp:

Code: [Select]$mailer = new PHPMailer();
$mailer-&

shift numbers with paging
Hi

How would i be able to display 10 numbers 1 2 3 4 5 6 7 8 9 10
and when I click next

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

how do i make a string??
hey guys,
can someone please tell me how to put data from the glob function into a string

Motivational Posters
Hello,

I wonder how can i do them in php. Are there any sample codes that you can show me?

Struct/union and scope problem!
HI all , I have
Code: in header.h typedef struct Node Link; /* ---------

Help on query replacing the date
Hi Pals,

i want to replace the current date in a column to some value say C or D or any n

Will this protect from mysql injection?
I do not want anything like DROP TABLE to work or any type of coding..

Heres my code.. is it

Reading waves
Hi,

I am trying to find a way of finding the highs and lows on a graph line, the line points