[Netem] Simulating a high-latency, low-bandwidth connection

[Justin Lebar]

Oh wow; I found the answer in the mailing list archives.

https://lists.linux-foundation.org/pipermail/netem/2010-May/001388.html

It would be terrific if the page were updated with the right commands.

Sorry for the spam!

-Justin

On Mon, May 31, 2010 at 4:52 PM, Justin Lebar <justin.lebar at gmail.com> wrote:
> I'd like to simulate a high-latency, low-bandwidth network connection
> over my loopback interface so I can test a Firefox feature I'm working
> on [1].
>
> I've managed to separately add latency and limit bandwidth with
> tc/netem.  But I haven't been able to combine these.
>
> There's a code snippet at [2] which purports to do exactly what I
> want, but when I run it, I get:
>
>    # tc qdisc add dev lo root handle 1:0 netem delay 100ms
>    # tc qdisc add dev lo parent 1:1 handle 10: tbf rate 256kbit
> buffer 1600 limit 3000
>    RTNETLINK answers: Operation not supported
>
> Surely what I'm trying to do must be possible.  Is there any way I can
> get more detail on what's going wrong above, or is there a different
> incantation I should try?
>
> I'm running Ubuntu 10.04, kernel 2.6.32-22, inside VirtualBox 3.1.8.
>
> Thanks for your help,
> -Justin
>
> [1] https://bugzilla.mozilla.org/show_bug.cgi?id=529208
> [2] http://www.linuxfoundation.org/collaborate/workgroups/networking/netem#Rate_control
>