Subject: Re: [RFC PATCH 1/4] net: port mirroring: add tracepoints to appropriate network paths

From: Stephen Hemminger <[email-masked]>
Date: Tue, 15 Dec 2009 09:22:22 -0800

On Tue, 15 Dec 2009 12:02:49 -0500
Neil Horman <[email-masked]> wrote:

> On Tue, Dec 15, 2009 at 08:44:24AM -0800, Stephen Hemminger wrote:
> > On Tue, 15 Dec 2009 11:36:04 -0500
> > Neil Horman <[email-masked]> wrote:
> > 
> > > Add net_dev_xmit & net_dev_receive tracepoints
> > > 
> > > Add tracepoints at the end of the network stack xmit path and the start of the
> > > stack receive path.  Among other uses, these tracepoints can be used to tap the
> > > raw input and output streams for any given network device for the purposes of
> > > mirroring that traffic to other ports.
> > > 
> > 
> > There already is a mirroring solution but people don't know how to use it.
> > Using mirred on ingress qdisc does that.
> > 
> I wish that had been easier to find.  That only appears to mirror inbound frames
> though, what about outbound frames? can you attach mirred to an outbound qdisc?

It works for outbound frames as well.