Message-ID: <4738D9AB.8080408@intel.com>
Date: Mon, 12 Nov 2007 14:54:35 -0800
From: "Kok, Auke" <auke-jan.h.kok@intel.com>
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To: Chris Friesen <cfriesen@nortel.com>
CC: David Miller <davem@davemloft.net>, kaber@trash.net, joonwpark81@gmail.com,
       netdev@vger.kernel.org, djohnson+linux-kernel@sw.starentnetworks.com,
       linux-kernel@vger.kernel.org, e1000-devel@lists.sourceforge.net
Subject: Re: [PATCH 2/2] [e1000 VLAN] Disable vlan hw accel when promiscuous
 mode
References: <47365200.0f10240a.0686.2173@mx.google.com> <47388988.1000506@intel.com>	<47388B9F.7050308@trash.net> <20071112.143342.10809862.davem@davemloft.net> <4738D70C.4060404@nortel.com>
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Chris Friesen wrote:
> David Miller wrote:
> 
>> When you select VLAN, you by definition are asking for non-VLAN
>> traffic to be elided.  It is like plugging the ethernet cable
>> into one switch or another.
> 
> For max functionality it seems like the raw eth device should show
> everything on the wire in promiscuous mode.
> 
> If we want to sniff only the traffic for a specific vlan, we can sniff
> the vlan device.

actually the impact can be quite negative, imagine doing a tcpdump on a 10gig
interface with vlan's enabled - all of a sudden you might accidentally flood the
system with a 100-fold increase in traffic and force the stack to dump all those
packets for you.

I'm still very reluctant about this patch, I think the current situation is OK for
everyone and offers everyone the possibility to do what they need, without hidden
consequences.

Auke
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