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;
}

No comments posted yet

Your Answer:

Login to answer
202 Like 12 Dislike
Previous forums Next forums
Other forums

RTF fomatting to email content
Im trying to sen an email with content is picked up from a rtf-file (file_get_contents('*.rtf'). Mai

need help in mysql_num_rows()
please tell me what i am doing wrong in this query. it displays this error

Code: Warning: mys

Trouble checking SESSION cookie
I am trying to use $_SESSION cookies to verify admin privileges .
I don't understand why this is

ctype() validation - allowing illegal characters
Hello,
I use ctype() to filter and validate a user form. However, I am trying to allow certain c

Help with setcookie()
Merry Xmas to those on this foruum
Older guy here with some experience but not allot so please be

Redirect not working after making a POST/GET
Hi Everyone,

I am a novice in PHP. Here I have 2 pages, one page with a textbox and button an

Help with file_get_html
The following code gives the expected results:

<html>
<head&g

Guixt issue
Hello all,

We are experiencing the following problem with Guixt:

Some transact

mysql_affected_rows() usage
Possibly a MySQL issue, but the function that is not behaving in the anticipated way is a PHP functi

Using the $_GET variable to view certain records
Hello,

First let me explain my problem, I have 2 pages the first page pull a list of Guide ti

Sign up to write
Sign up now if you have flare of writing..
Login   |   Register
Follow Us
Indyaspeak @ Facebook Indyaspeak @ Twitter Indyaspeak @ Pinterest RSS



Play Free Quiz and Win Cash