We tested RB750 (for usability in our project) and we discovered "kernel failure" by heavy load trough configured hw switch. We reproduce it on second RB750 unit, it looks like a bug.

Configuration of tested RB750:
/system reset-configuration no-defaults=yes skip-backup=yes;
/interface ethernet set ether4 master-port=ether5;

Test environment:
ether1 of RB750 - connected to LAN, one Winbox connection to RB750
ether4 of RB750 - connected to ether1 RB433AH, v3.22, 10.0.0.1/24
ether5 of RB750 - connected to ether1 RB433AH, v3.24, 10.0.0.2/24
both RB433AH was in clear state (/system reset-configuration no-defaults=yes) with only IP assigned.

Test launching on RB433AH with IP 10.0.0.2:
/tool bandwidth-test 10.0.0.1 protocol=udp direction=both local-udp-tx-size=1460 remote-udp-tx-size=1460

Test results:
- traffic trough RB7500 was growing up from zero to cca 96Mbps (both direction) and stay on this level, cca 8000pps (both direction)
- after 20-25s of running test communication trough hw switch was interrupted, communication with RB750 via ether2, ether3, ether4 and ether5 was not more possible (only via ether1)
- after next cca 20-60s RB750 was automatically rebooted
- after login to rebooted RB750 there was echo on terminal with log messages:
jan/02/1970 00:00:12 system,error,critical System rebooted because of kernel failure
jan/02/1970 00:00:12 system,error,critical router rebooted without proper shutdown, probably power outage

Test we did more time on two RB750 unit, always with the same result. Only time to automatically reboot was different.

If it is Kernel failure you need to make supout.rif (or just take autosupout.rif) and send it to support@mikrotik.com.

If it is Kernel failure you need to make supout.rif (or just take autosupout.rif) and send it to support@mikrotik.com.

I sent it now.

But, regarding Mikrotik communication policy, I do not have a right to do it. As lot of people around, we bought all licenses and routerboards from shopkeepers in our country. Sending anything about technical support/problems to shopkeepers is fruitless (IMHO). Mikrotik should have same kind of bugzilla, I understood they use forum for it.

Don't worry, you can contact MikroTik if it's some kind of a kernel issue that the distributor can't fix

Mikrotik should have same kind of bugzilla, I understood they use forum for it.

support at mikrotik.com is prefiltering for internal bugzilla =)

and don't worry - bugreports are always welcome, because it helps in making ROS better