2

I'm setting up a test to saturate a link between two machines with a gig router in between them, then run fq_codel on Debian Buster and see if my ping times can improve (what I think fq_codel is supposed to do if it's working).

On machine A I force my NIC to 10Mbps like

ethtool -s enp8s0 advertise 0x002

Then my gigabit router shows the link speed of this box as 10Mbps. Then I try to ping machine B and get times of around 0.5ms, then to saturate the link I do

dd if=/dev/urandom | ssh user@192.168.10.150 dd of=/dev/null

Then I get pings of around 10ms. Then I try to enable fq_codel like:

tc qdisc add dev enp8s0 root fq_codel

But my pings stay at around 10ms. So I try to see what enp8s0 is doing, here's what I get:

tc qdisc show dev enp8s0
  qdisc fq_codel 8001: root refcnt 6 limit 10240p flows 1024 
  quantum 1514 target 5.0ms interval 100.0ms memory_limit 32Mb ecn

What am I doing wrong, or how can I test better, or understand what's happening?

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.