Hello
RB2011UiAS-2HnD-IN with 3.14 / 6.12 working as PPPoE client to VDSL2 line (30 Mbit/s down)
10 clients connected via DHCP all doing almost nothing (in terms of bandwidth usage).
1 client downloading at 3,5 MB/s.
Is this CPU usage normal? Spikes from 5% to almost 70% every now and then?
Watch the video here:
https://www.youtube.com/watch?v=jWS2dQbpNJg
Barty
Look in /tool profile what service is consuming the CPU
ethernet, firewall, networking. These three are spiking causing heavy load. Don’t know if there is anything I can do to prevent such high load (example now: 1 client connected, downloading at 3.6 MB/s ~ 30 Mbit/s) - CPU usage as shown on vid.
CPU at 66% wouldn’t be a big issue.
Anyway, it seems a bit strange because it looks as if you are using only small packets. According to Mikrotik, this router should hit 40Mbps tested with 64byte packets. With larger packets it can reach a lot more obviously.
Try to find out what kind of traffic is passing through, see if it is udp or tcp, drop invalid packets in firewall (if you are not doing so already). Look at the firewall filters rules which rule has more hits and investigate that traffic.