problem with UDP broadcast on Windows XP

[Paul McGuire]

On Apr 10, 3:30 pm, Irmen de Jong <irmen.NOS... at xs4all.nl> wrote:
> > Hendrik van Rooyen wrote:
> >> I am not sure if this is at all relevant - but I seem to recall seeing
> >> something once that had a list of socket numbers, splitting them
> >> between UDP & TCP - can the socket actually rx UDP?
> Yeah, as I wrote: when I'm sending UDP packets to the port directly
>
> on the server's IP address, it responds just fine.
>
> It's just the broadcast packets that don't seem to arrive.
> (sent to ('<broadcast>',9090) )
>
> Steve Holden wrote:
> > It's most likely, I suspect without knowing to much about it, that the
> > service is stalling because of a failure to "pump" Windows messages.
> > Irmen, are you taking any action in your service to ignore Windows
> > messages that your service process receives?
>
> Hm, seeing that it processes TCP and "directed" UDP packets just fine,
> there shouldn't be a problem here?
>
> No I'm not knowingly doing stuff that ignores windows messages...
>
> (I could maybe put up the code if someone wants to take a look but
> not right now. Need to rip a fair deal out - there's a lot of
> other stuff in there that's not relevant to the problem.)
>
> --Irmen

I would investigate Windows security settings as a likely culprit.  My
guess is that you are running WinXP SP2 with the default security
policies, which are likely to prohibit such promiscuous behavior.

Here's a URL that may shed some light, it seems surprisingly
instructive for MS support: http://support.microsoft.com/kb/842242 -
Some programs seem to stop working after you install Windows XP
Service Pack 2

-- Paul