RB750, v4.2 and kernel failure (heavy load trough hw switch)

RouterOS General
1

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.

2

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

3

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.

4

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

5

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

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