Re: Broadcast traffic on vlans leaks into the parent interface on NetBSD-5.1

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Wed, Nov 28, 2012 at 07:23:13PM -0600, David Young wrote:
> On Wed, Nov 28, 2012 at 07:27:56PM -0500, Greg Troxel wrote:
> > 
> > dhcpd, last I checked, used bpf and not sockets.
> > 
> > If dhcpd is bpf, I would suggest reading the bpf_tap calls in the
> > driver.  It could be that if_wm.c has a spurious on.
> > 
> > If it's not, I don't know what's going on.
> 
> I'll bet this has something to do with the hardware VLAN tagging.  I
> don't think BPF groks the VLAN mbuf tags.
> 
> FWIW, I think that hardware VLAN tagging is a lot of pain for no gain
> the way that NetBSD is doing it.

The last time I looked at this (on wm(4) with not-so-fast CPUs),
hardware vlan tagging had a small gain. Not much, but still measurable

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--