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@ 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?

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