CentOS - Apr 2015 - tc seems to have no effect on the NIC's

Hello all,

We have installed this network testing environment:

https://github.com/facebook/augmented-traffic-control

which seems pretty nice overall.

It allows you to artificially degrade your network performance by issuing
tc commands to directly affect your networking.

I have it set up on two CentOS 6 machines - one a Dell server, one a
VirtualBox VM. The tc syntax seems OK, it seems to all make sense - only it
seems to have no effect whatsoever on the actual network performance.

Hence the question: is there a known issue with tc? Am I perhaps missing
some kernel modules, or do I perhaps now have some kernel parameters set
correctly?

Any insight will be helpful.

Thanks in advance,

Cheers,

Boris.

On 01-04-2015 13:16, Boris Epstein wrote:
> Hello all,
>
> We have installed this network testing environment:
>
> https://github.com/facebook/augmented-traffic-control
>
> which seems pretty nice overall.
>
> It allows you to artificially degrade your network performance by issuing
> tc commands to directly affect your networking.
>
> I have it set up on two CentOS 6 machines - one a Dell server, one a
> VirtualBox VM. The tc syntax seems OK, it seems to all make sense - only it
> seems to have no effect whatsoever on the actual network performance.
>
> Hence the question: is there a known issue with tc? Am I perhaps missing
> some kernel modules, or do I perhaps now have some kernel parameters set
> correctly?
>
> Any insight will be helpful.
Hi Boris,

Maybe it's just not matching your traffic and thus putting it in the 
main class, lets say.

You can check how it's going on with
     tc -s qdisc show dev DEV
and
     tc -s class show dev DEV
Both have some interestings stats that you can watch using watch -d and 
check through where your traffic is flowing.

If the numbers you want to are not changing, you're probably missing the 
tc filters for matching them.

   Marcelo