Strange problem with sk0

[Pyun YongHyeon]

On Fri, Oct 22, 2010 at 05:09:33PM -0400, Mikhail T. wrote:
>  Hello!
> 
> I have a rather bizarre problem with my on-board sk interface... It only 
> works, when tcpdump is running...
> 
> Seriously. It negotiates with the switch (1000baseT/full-duplex) just 
> fine, but, unless tcpdump has it open (and in "promiscuous" mode), no 
> traffic seems to go through. It would not respond to pings -- not even 
> from the switch itself, nothing.
> 
> But, as soon as I start tcpdump -- even if tcpdump never has anything to 
> output:
> 
>    tcpdump -i sk0 -n src host 10.non.existent.IP
> 
> Traffic starts flowing just fine... Do I simply have flaky hardware? The 
> motherboard is old, and, for some reason, I need to "remind" sk0, what 
> its ethernet address upon reboote (it starts off with 00:00:00:00:00:00).
> 
> Any other explanations for what is happening? There are plenty of other 
> systems (computers, VoIP phone, two TVs) on this switch and all are 
> fine... I did try different ports on it -- same results. I also tried 
> forcing things down to 100/half-duplex -- no change...
> 
> Thanks! Yours,
> 

FYI: Fix committed to HEAD(r214898, r214899). Will MFC after 1
week.