Our office has one RB4011iGS+ device which becomes unresponsive at random times.
During those times, CPU usage jumps to 10% - normally it is below 3% (approximation from graph image). No abnormal logs are visible (device is pushing all logs to a local syslog server)
Only thing that helps is hard resetting the device. Sometimes (on rare occasions), SSH still works, but with delay between keystrokes, and the device can be reset this way.
Device handles at most 2 VPN users at any time, has only tree firewall rules (allow L2tp/IPSec on input, and deny all on input)
Also, there are 3 VLANs on SFP+, but the traffic is only 150mbps at peak times.
I have tried upgrading to the latest stable RouterOS version, and to the latest Firmware version. This doesn't seem to help.
Device is 4 months old.
Did anyone have the same situation, and how were you able to resolve it?