Take the 2-minute tour ×
Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free, no registration required.

In order to facilitiate some performance testing I am attempting to throttle the ip traffic on a particular machine - I want limit it to 1Mbit/sec.

I have a separate test machine where this command works just fine:

tc qdisc add dev eth0 root tbf rate 1mbit burst 5kb latency 70ms peakrate 1.001mbit minburst 1540

On the real box where I want to apply this, I get weirdness. The exact same command limits traffic to 6Kbit/sec. Any ideas why?

unanme -a shows

Linux IPERF1 2.6.18-128.el5PAE #1 SMP Wed Dec 17 12:02:33 EST 2008 i686 i686 i386 GNU/Linux

We have a three different ways of monitoring the throughput: The actual application we are testing which reports the throughput we see. We also some Tivoli monitoring on a switch and we have an HTTP client which downloads a file from an HTTP server on the box in question. All three methods show 6Kbs when the TBF is applied, and many Mbs when we remove the TBF.

share|improve this question

1 Answer 1

Timer resolution might influence your results, see here for example. What happens if you increase burst to 10kb and remove peakrate and minburst?

share|improve this answer
    
Unfortunately I can't go back and check this. I'm pretty sure your idea is correct. –  djna Oct 13 '10 at 20:34

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.