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

Undefined Variable: PHP_SELF, pls help
Hi,

Im a newbie on PHP / MySQL programming and Im running a script to search one field on my

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

Adding to the next element in a multidimensional array
Hi, I'm trying to add a value to $node->field_spaces['nid'] where x is the next available spo

Search in the PHP Files
have to search asterisk(*) in the php code of the php files .
In the html page one text box

php call servlet
I have done a php backup application .
So there is a form that user pick some files to zip and d

how make 2 column in table with data tybe long row
hi every one

I want make in my table 2 column with data tybe long raw

how thi

my sql select id and then update problem.
I need to select some auto incremented ids out of a database and then use those id in a where statem

Php If in MySql query (hiding labels if a field is empty)
Okay, I've been trying to do this for a while, and I'm finally going to ask for help so I can get th

Getting Subdomain Name With PHP?
I want to grab the subdomain name with PHP so I can generate database queries.

for example my

Converting RGB values to HEX
Code: <?PHP

$file_handle = fopen("colors/rgb.csv", "r");

wh