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 firstname.lastname@example.org 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?