Re: vb6.0 udp multicast problem

Tech-Archive recommends: Repair Windows Errors & Optimize Windows Performance

emp1953 wrote:
I have a UNIX machine broadcasting and receiving messages via UDP
multicast.

I have configured a vb6.0 app with a winsock control configured
haphazardly. I say haphazardly because there are no winsock udp
multicast examples 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 with UDP for
broadcast in a mixed Windows / Irix environment. As far as I know, you
should be able to do this using broadcast to a multicast IP range
(assuming you're on the same network segment).

What does netstat -nr show for the multicast range? (224.xxx etc). IOW
are you sure there's a route from multicast to 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 over UDP. Anything newer than
Win2K SP1 should be OK.

--
Jim

.

Relevant Pages

  • vb6.0 udp multicast problem
    ... I have a UNIX machine broadcasting and receiving messages via UDP ... I have configured a vb6.0 app with a winsock control configured ... multicast examples in any Microsoft documentation or any where else ...
    (microsoft.public.vb.general.discussion)
  • receiving mjpegs over tcp and multicasting decoded rgb images slows network down?
    ... jpegs as rgb images via udp into the local network. ... udp multicast socket. ...
    (comp.os.linux.networking)
  • Re: is using applet-servlet communication to implement realtime features possible?
    ... UDP messages and, if so, from whom. ... SecurityManager.checkMulticastcode would throw an exception for an Applet ... Multicast socket ... Connect to the Application Server and pass authorization via a) ...
    (comp.lang.java.programmer)
  • Re: SLP in MFC
    ... But as far as the multicast ... section 6.1, it appears that SLP can run over UDP or TCP, and as UDP then ... The issue being that if a packet would exceed the maximum UDP ...
    (microsoft.public.vc.mfc)
  • UDP checksum broken, -head and releng_8
    ... When sending multicast packets to a socket that is _not_ ... this generates bad UDP ... And on another box, use tcpdump to see the bad checksums, ...
    (freebsd-current)