IP Multicast (just 'casting, not rcving)

[Smith, Gene]

All I had to do was, in my driver attach fn, set the flag IFF_MULTICAST.
Now it sends a multicast!  However, this still does not cause the driver to
support receiving a multicast (which I don't need).  Seems like there should
be separate flags for saying that the interface can send multicasts (it
seems like all could?) and that the interface can receive them. 
-Gene

> -----Original Message-----
> From: Smith, Gene [mailto:Gene.Smith at sea.siemens.com]
> Sent: Monday, February 05, 2001 3:46 PM
> To: rtems-users at oarcorp.com
> Subject: IP Multicast (just 'casting, not rcving)
> 
> 
> A while back I asked if multicast was supported in rtems. I have since
> realized that I only need to transmit multicast messages, not 
> receive them.
> Does anyone know if rtems might support just sending a 
> multicast? When I
> try to send a udp packet to a multcast address, eg, 
> 224.0.1.100, my current
> udp code fails in send() with "Network Unreachable" and nothing is
> transmitted on the network per tcpdump. Perhaps I need to set a socket
> option to tell it the multicast interface, although Steven 
> seems to says you
> don't need to set socket options or join a group to just send 
> a multicast.
> Any ideas while I continue reading rtems-bsd code and Stevens? 
> 
> -Gene
> 
> > -----Original Message-----
> > From: suvrat gupta [mailto:suvrat at utstar.com]
> > Sent: Tuesday, August 01, 2000 5:16 PM
> > To: Smith, Gene
> > Subject: Re: IP Multicast
> > 
> > 
> > I looked at it about two months ago. Seemed like most of the 
> > IP stack does
> > support it..  The ethernet driver needs to support multicast related
> > ioctls(add/remove address in the H/W filter).this can be done 
> > by usingl
> > ether_addmulti() ether_delmulti() functions(you may need to 
> > modify them a bit.
> > Try using the latest RTEMS code.
> > hope this helps. In case you do come to know of some working 
> > implementation,
> > let me know.
> > -suvrat
> > 
> > "Smith, Gene" wrote:
> > 
> > > Is IP Multicast actually supported in RTEMS?  If so, has it 
> > been used by
> > > anyone?  All the drivers in "network" directories seem to 
> > say FIXME and
> > > ERROR when referring to multicast.  I didn't see multicast 
> > mentioned in
> > > Networking Suppliment.
> > >
> > > My application might need some form of multicast.  However, 
> > a simple subnet
> > > broadcast might do.
> > >
> > > -Gene
> > 
>