Using SQM and NetEm on the same interface?


I seem to have an issue with adding netem to SQM link.

# tc qdisc
qdisc noqueue 0: dev lo root refcnt 2
qdisc fq_codel 0: dev eth0 root refcnt 2 limit 10240p flows 1024 quantum 1514 target 5.0ms >interval 100.0ms memory_limit 4Mb ecn
qdisc cake 1: dev eth1 root refcnt 2 bandwidth 28500Mbit besteffort dual-dsthost nonat nowash >no-ack-filter split-gso rtt 100.0ms noatm overhead 40 mpu 98
qdisc noqueue 0: dev br-lan root refcnt 2
qdisc noqueue 0: dev eth0.1 root refcnt 2

When I do tc qdisc add dev eth1 parent 1: netem delay 20ms it says
"RTNETLINK answers: Not supported"

Could anyone explain why that happens?

I don't think cake supports a hierarchy of qdiscs below it. your experience seems to confirm that