Subject: Re: change the way e1000 is handling short VLAN frames

From: jamal <[email-masked]>
Date: Fri, 21 Sep 2007 07:59:06 -0400

On Fri, 2007-21-09 at 09:31 +0200, Emil Micek wrote:
> Hello list,
> 
> I'd like to change behaviour of e1000 module when transmiting short
> ethernet frames (shorter then 64 bytes) trough VLAN interface.
> 
> Current e1000 (according to our observations) first appends 4 bytes of
> VLAN tag and then pads the frame to 64 bytes with zeroes if necessary
> before transmiting it.

Which would make it a bug. AFAIK, the minimum VLAN tagged packet going
out is 68 bytes.

> I'd like to change it so it first pads the frame to 64 B and appends the
> VLAN tag afterwards, so the resulting VLAN frame would be 68 bytes
> minimum.

If you were able to figure this much out: What have you tried and what
do you still need help on? CCing some of the e1000 people(done) will
probably help you get this resolved faster.

cheers,
jamal