100% CPU Utilization SNMP and Management RB750G

RouterOS General
1

See attached graph. This router works for months on end and then goes into a 100% CPU loop. We do

/tool profile

and see that the following services are spiking:

SNMP and Management.

NAME                    CPU        USAGE
ppp                     all           0%
p2p-matcher             all         0.5%
snmp                    all        31.5%
ethernet                all           8%
console                 all           0%
traffic-flow            all         1.5%
firewall                all           3%
logging                 all           0%
management              all        47.5%
idle                    all           2%
queuing                 all           6%
unclassified            all           0%

Our conclusion:

  1. SNMP server is broken
  2. Management (what does this entail?) is broken
  3. SNMP client is broken

As for option 3, this only happens on MikroTik, as far as we know.

Solution: Stop using SNMP on RB750G with RouterOS :frowning:

Other specs:

RouterOS v5.24
Firmware: 3.02
At 12:05 we turned off SNMP and CPU is back to normal.

Advice welcome.

Maybe install SNMP and Management watchdog? How?
chart (3).png

2

Hi Eugene,

do you use pppoe authentication?i have stumbled across same issue every now and again although i replicate the problem by disconnecting pppoe sessions and once they connected again the cpu usage goes up even though no traffic is passing through pppoe connection,almost as if its a broadcast storm of some sort.i know in my case that its not snmp as the issue was present before we implemented a snmp server,its puzzling though that you and i have the same issue but different causes.This issue is only present on highsites using rb750g

3

I am seeing similar issues with Cacti watching these devices using SNMPv3. When enabled CPU is excessive upwards of 90% however when I disable SNMP it goes down by 9%.

Nothing crazy running, a couple static routes as well and three or 4 internal BGP routes and this is a CCR-1016

Open for suggestions.