Re: vb6.0 udp multicast problem

On Oct 7, 9:34 pm, "Jim Mack" <jm...@xxxxxxxxxxxxxxx> wrote:
emp1953 wrote:
I have a UNIX machine broadcasting and receiving messages viaUDP
multicast.

I have configured a vb6.0 app with a winsock control configured
haphazardly.  I say haphazardly because there are no winsockudp
multicastexamples in any Microsoft documentation or any where else
for that matter.

I can send messages to the Unix machine, it receives them and parses
them perfectly.  Messages coming back are not received by the vb6.0
app.

Can you show the code you use to configure the winsock control, and
any static setup of the properties? I use winsock withUDPfor
broadcast in a mixed Windows / Irix environment. As far as I know, you
should be able to do this using broadcast to amulticastIP range
(assuming you're on the same network segment).

What does netstat -nr show for themulticastrange? (224.xxx etc). IOW
are you sure there's a route frommulticastto your host, on the
Windows side?

Also, depending on the age of the OS and the stack, you may need to
call setsockopt() to allow broadcast overUDP. Anything newer than
Win2K SP1 should be OK.

--
        Jim

Jim, Keep in mind that the UNIX box is broadcasting multicast and
other LINUX and UNIX machines on the LAN are reading it fine.
Oh, it is a closed local network, 4 machines running through an
ethernet switch, my PC will make it 5. Where is the setsocketopt()
call? on the UNIX side? That seems to work fine already with the non-
windows machines.

Here's the code - not much to it:


udpRemoteHost = "224.0.10.101"
udpRemotePort = 6301
Me.udpServer.Bind 6300
Me.udpServer.RemoteHost = udpRemoteHost
Me.udpServer.RemotePort = 6301

I did the netstat -nr on the PC. what am I looking for. I couldn't
copy and past the results here. I took a .bmp of it but can't post
that here either.
I could email it to you.

Thanks, Ed


.

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