Subject: Re: gsip sends byte-swapped vlan tags
To: None <firstname.lastname@example.org>
From: Pavel Cahyna <email@example.com>
Date: 01/25/2006 20:50:31
On Wed, Jan 25, 2006 at 08:33:57PM +0100, Manuel Bouyer wrote:
> On Wed, Jan 25, 2006 at 08:01:47PM +0100, Pavel Cahyna wrote:
> > On Wed, Jan 25, 2006 at 07:50:57PM +0100, Manuel Bouyer wrote:
> > > On Wed, Jan 25, 2006 at 12:22:06PM +0100, Pavel Cahyna wrote:
> > > > the itended effect...
> > > >
> > > > What is the purpose of hardware VLAN tagging, anyway? The performance
> > > > impact will be rather negative, because searching the VLAN tag in the
> > > > linear list of mbuf tags will be probably slower than simply prepending it
> > > > to the mbuf. It also seriously limits usability of tcpdump (tcpdump sees
> > >
> > > I can tell you that it has a positive inpact on a Alpha DS20 with a
> > > gigabit interface; I get a 10% increase with tcpdump.
> > tcpdump?
> Sorry, I meant ttcp
Do you have any explanation why does it help?
Could be HW tagging made conditional on some setting, like hardware
checksums (if the hardware allows turning them off)?