Can I use TCP BBR with Cake?

So default qdiscs are obviously a matter of taste. That said as a rule of thumb I would say:
sch_fq: great default qdisc for end hosts, preferably endhost without virtual machines running
sch_fq_codel: great all around qdisc
cake: great for wan links, but computationally expensive with little advantages over fq_codel for LAN links.

When systemd discussed default qdiscs cake's main developer argued against cake on every interface, but again a matter of taste.

Regarding BBR, as far as I can tell, BBR has some issues with AQMs like SQM as it ignores ECN marks and also tries to ignore packet loss up to certain limit. Some version of BBR gained a special AQM detection mode which might work better with SQM. That said unless your router actually initiates/terminates loads of TCP connections the choice of TCP CC probably does not matter much.

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