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From: Andrew Lunn <andrew@lunn.ch>
To: David Miller <davem@davemloft.net>
Cc: olteanv@gmail.com, f.fainelli@gmail.com,
	vivien.didelot@gmail.com, netdev@vger.kernel.org
Subject: Re: [PATCH net-next] net: dsa: Allow port mirroring to the CPU port
Date: Thu, 3 Oct 2019 21:09:07 +0200	[thread overview]
Message-ID: <20191003190907.GC21875@lunn.ch> (raw)
In-Reply-To: <20191003.120457.1626857609490915856.davem@davemloft.net>

On Thu, Oct 03, 2019 at 12:04:57PM -0700, David Miller wrote:
> From: Vladimir Oltean <olteanv@gmail.com>
> Date: Thu,  3 Oct 2019 02:37:50 +0300
> 
> > On a regular netdev, putting it in promiscuous mode means receiving all
> > traffic passing through it, whether or not it was destined to its MAC
> > address. Then monitoring applications such as tcpdump can see all
> > traffic transiting it.
> > 
> > On Ethernet switches, clearly all ports are in promiscuous mode by
> > definition, since they accept frames destined to any MAC address.
> > However tcpdump does not capture all frames transiting switch ports,
> > only the ones destined to, or originating from the CPU port.
> > 
> > To be able to monitor frames with tcpdump on the CPU port, extend the tc
> > matchall classifier and mirred action to support the DSA master port as
> > a possible mirror target.
> > 
> > Tested with:
> > tc qdisc add dev swp2 clsact
> > tc filter add dev swp2 ingress matchall skip_sw \
> > 	action mirred egress mirror dev eth2
> > tcpdump -i swp2
> > 
> > Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
> 
> Andrew and co., please review.

Yes, i thinking about this. Not reached a conclusion yet.

     Andrew

  reply	other threads:[~2019-10-03 19:09 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-02 23:37 Vladimir Oltean
2019-10-03 19:04 ` David Miller
2019-10-03 19:09   ` Andrew Lunn [this message]
2019-10-03 19:24 ` Andrew Lunn
2019-10-03 21:21   ` Vladimir Oltean

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