On Fri, 2011-12-23 at 17:16 +0100, Eric Dumazet wrote:

Le vendredi 23 décembre 2011 à 10:26 -0500, John A. Sullivan III a
écrit :

quoted

Yes.  This is a problem I have with netem on ingress traffic.  I use the
filter on ffff: to redirect to ifb0 for the ingress traffic shaping.  I
cannot figure out a way to redirect a second time to ifb1 for the netem
qdisc.  I tried putting two action mirred statements in the filter but
that did not work.  Unlike eth1, I cannot attach a filter further down
the ifb0 hfsc hierarchy because one can't redirect one ifb into another
ifb.  Thus, the only way I could figure out how to do inbound netem was
to replace the terminal qdisc with netem rather than SFQ.  I'd love to
be able to do that differently.  I tried attaching netem to the SFQ but
that failed (I assume because SFQ is classless) and I tried the other
way around, attaching SFQ to netem since you mentioned netem could take
a class but that did not work either.

Unfortunately, netem wants to control skbs itself, in a fifo queue.

To implement what you want, we would need to setup a second qdisc,
and when packets are dequeued from internal netem fifo, queue them in
second qdisc.

I thought I tried to do that but I must have done it incorrectly.  I
would think something like:

tc qdisc add dev eth1 ingress
tc filter add dev eth1 parent ffff: protocol ip prio 50 u32 match u32 0 0 action mirred egress redirect dev ifb0
tc qdisc add  dev ifb0 root handle 4 netem delay 25ms 5ms distribution normal loss 0.1% 30%
tc qdisc add dev ifb0 parent 4:0 handle 1: hfsc default 20

but I get:
root@testswitch01:~# tc qdisc add dev ifb0 parent 4:0 handle 1: hfsc default 20
RTNETLINK answers: Operation not supported

What did I do wrong? Thanks - John