RE: qt multi- and broadcast (was Re: dhcpcd not working in simh-vax with xq0:nat networking)

[Mark Pizzolato - Info Comm <Mark%infocomm.com@localhost>]

On Sunday, December 12, 2021 at 10:17 AM, Rhialto wrote:
> On Sun 12 Dec 2021 at 17:16:17 +0000, Mark Pizzolato - Info Comm wrote:
> > We never got any complaints from any other DEC operating system,
> > but many/most/all of these may never have attempted to put the
> > device into DELQA-T mode and just ran the device as a vanilla DEQNA.
> 
> Or maybe the DELQA-T driver did it like DELQA-normal and included the
> broadcast, like in the examples from the documentation.

The initialization interface for the DELQA-T mode doesn't include an 
address list like the DEQNA.  It just provides for the single interesting
MAC address.  The DEQNA absolutely requires the broadcast address to 
be in the address list if the driver/os wants to get broadcast 
packets.  The rest of the address list is used for multi-cast addresses 
unless there are too many interested multi-cast addresses and then the 
all-multicast mode is selected by the OS and it filters multi-cast traffic in
the kernel.

> > > Still, I think that in any case the NetBSD qt driver lies when it says
> > > it supports IFF_MULTICAST.  It doesn't even support IFF_ALLMULTI (in
> the
> > > above code represented by all_multicast).
> >
> > I would think that would be a problem in NetBSD...
> 
> Yes...

How does NetBSD generally handle multi-cast?  What interfaces exist to 
NIC drivers to express the desire to receive all or particular multi-cast 
packets?

- Mark