I reviewed the latest sources of Linux, FreeBSD and NetBSD.
They all reset the multiple IA bit (multi_ia in BSD) to zero,
but I did not find code which sets this bit to one
(like it is done by some routers).

Running Windows guests also did not set this bit.

Intel's Open Source Software Developer Manual does not
give much information on the semantics related to this bit,
so I had to guess how it works. The guess was good enough
to make the router emulation work.

Related changes in this patch:
* Update naming and documentation of the internal hash register.
  It is not limited to multicast, but also used for multiple IA.
* Dump complete configuration register when debug traces are enabled.
* Debug output when multiple IA bit is set during CmdConfigure.
* Debug output when frames are received because multiple IA bit is set,
  or when they are ignored although it is set.

Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>