kern/141646: [em] em(4) + lagg(4) + vlan(4) generates ISL-tagged frames instead of 802.1q-tagged frames

[Jack Vogel]

Fix is just checked into HEAD,  its sort of a workaround, but really a
pretty acceptable one. Let me know if it works for you.

Jack


On Fri, Jan 29, 2010 at 3:59 PM, Jeff Blank <jfb at mr-happy.com> wrote:

> On Fri, Jan 29, 2010 at 02:47:39PM -0800, Jack Vogel wrote:
> > What's with the encrypted messages entered in this bug suddenly?
>
> Just base64-encoded plain text--it appears GNATS is not base64-aware.
> To summarize (I received a copy directly), Mr. Anishchuk is
> experiencing the same problem and suggested a workaround (also posted
> to the list previously) involving "ifconfig_emN='-vlanhwtag up'" in
> rc.conf.  He also seemed to think it was twice-Q-tagged frames rather
> than ISL-tagged frames, which does not match my packet captures.
>
> > An important update - I have root caused this. Turns out its kinda
> > interesting.
> > The reason there is a problem is due to the stacked pseudo devices, since
> > the vlan device is on lagg, and not directly on em, the em driver is not
> > getting
> > the "event" of the vlan attachment, and thus the vlan hw filter routine
> is
> > never
> > run, that routine sets a CRITICAL bit in the control register which
> > differentiates
> > between ISL and 802 tags... and thus our failure :(
> > The question now is what to do about this, I am thinking about this
> now....
>
> Interesting indeed.  I look forward to a fix (and have alternate
> interfaces and -vlanhwtag in the mean time).
>
> thanks,
> Jeff
>