kern/145905: [fxp] multicast packets aren't received when PROMISC mode on fxp.

[Bruce Simpson]

Spooky

http://en.wikipedia.org/wiki/Cisco_PIX

Some Intel-based Ethernet cards for the PIX are identified at boot with 
the designation "mcwa". This designation denotes a multicast 
<http://en.wikipedia.org/wiki/IP_multicast> receive bug 
<http://en.wikipedia.org/wiki/Software_bug> in the card's firmware that 
the designers addressed with a feature they called *M*ulti *C*ast *W*ork 
*A*round.

...I've seen this happen with 1 fxp card I used to have, I don't know if 
this was a recycled PIX part or not. Think it was 82559ED off the top of 
my head.