Re: IFB and bridges

W dniu 2011-12-12 01:42, John A. Sullivan III pisze:

----- Original Message -----

quoted

From: "Eric Dumazet"<redacted>
To: "John A. Sullivan III"<redacted>
Cc: netdev@vger.kernel.org
Sent: Sunday, December 11, 2011 5:00:59 PM
Subject: Re: IFB and bridges

Le dimanche 11 décembre 2011 à 17:38 -0500, John A. Sullivan III a>

quoted

I know IFB is often used for ingress but I wasn't really thinking
of
ingress filtering.  Let's say I have a 12 port Linux switch.  If
any
of the ports become backlogged, I want them to prioritize time
sensitive traffic so I implement traffic shaping but I don't want
to
have to define my qdiscs, classes, and filters 12 times over if
they
are all the same.  So I would direct each port to an IFB (not sure
if
that's intolerable overhead), have a single set of qdiscs, classes,
and filters, and, once those are applied, the packet arrives back
on
the same interface and proceeds assuming if has not been dropped or
delayed. - John

Really ? How are you going to shape a single IFB device, if you
really
have independant 12 ports. (Its a switch, not a hub after all)

A script can define your qdiscs/classes/filters hundred times, or one
thousand times, and writing such a script is far more easier than
setup
IFB.

<grin>  That's why I thought I'd ask the experts :) - John
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Also directing all traffic from all 12 ports is not good idea :)
It is performance killer

IFB can't handle too much pps

Also - You can't have too many tc filters/classes on one single IFB 
device because this is also performance killer.