Are there known issues with multicast on Intel Pro 1000?

[gnn at freebsd.org]

At Thu, 17 Jan 2008 15:06:19 -0500,
randall wrote:
> 
> gnn at freebsd.org wrote:
> > Howdy,
> > 
> > At my current gig we find that the network interface locks up if we
> > subject it to a high rate of multicast traffic.  Since the whole
> > purpose of this box is to do multicast (it absorbs a feed of data over
> > multicast manipulates and then sends it out again over multicast) it's
> > a "bad thing" if this kind of thing does not work.
> > 
> > What I currently know is not complete but I figured I could start
> > here.
> > 
> > The symptom is that all network communication stops, but the system
> > itself is still responsive, so I can get to the console and get
> > information.
> 
> If you let it run long enough does it eventually lock up?
> 
> I have seen similar behavior when a lock is not released when
> I was breaking things :-)
> 
> Everything is fine EXCEPT the interface.. for a while.. then
> eventually you get a train-wreck :-)
> 
> I would drop to ddb and do the show locks..
> 
> Also I believe top (or ps) will tell you what locks are being
> waited on in a course way... I think the ps in DDB will do this.

On closer inspection it looks like an "out of mbufs" situation and so
the right answer is to "up the nmbclusters" but there seem to be other
issues with this code and multicast so I'm likely to jump into DDB and
look more closely at it, likely next week.

Thanks,
George