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

Unable to display contents in Second Drop Down Box
Hi All,

What I am trying to do is 2 dependent drop down boxes and when user selects su

Looking for help reading a .txt or .ini file and outputting the info.
I have a file called Info.ini and It has the following info:
Code: [General]
Online=0
I wou

PHP error (line 38) my website
Hello everyone, I'm new on this
and I got a web site thats got a error not showing the photos on<

php title problem
Hi,

I am having a problem managing my page title with PHP.

Currently I have my <

is this the proper use of mysql_real_escape_string() to prevent sql injections?
i was wondering is this the proper use of mysql_real_escape_string() to prevent sql injections? any

remove a ; from emails in textarea
Code: <?php

session_start();

$database_host = "localhost&qu

getAlexaRank($url) function not working
I have made a function to get alexa rank
the site is here: http://mytestsite.rack111.com/1

Posting to another Site?
I have software that people install.
When they install it, is there a way to make it post their d

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

mysql VARCHAR acting like INT
Hi, All.

I have a table that contains a varchar(10) column named weird_field. In this column