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High CPU usage.

Posted: Fri Apr 06, 2018 11:46 am
by erlan
Help to deal with the problem of high load (up to 100%) of the processor on the CRS112-8G-4S.
There are up to 10 pppoe customers.

Re: High CPU usage.

Posted: Fri Apr 06, 2018 1:03 pm
by krautzj
Even though the CRS112-8G-4S can be configured to be a router and firewall, it is not well suited for it. I think you'll find the problem you have with the high load on the CPU is because the CPU in the CRS112-8G-4S is simply not powerful enough for queues and firewall rules. You would have better results if the routing, queues and firewalls were done by a dedicated router, and the switch was used only for switching.

From looking at your firewall rules it seems like you must already have a router somewhere that manages Internet access. You could try moving some of your configuration to that device and see if it helps.

Re: High CPU usage.

Posted: Fri Apr 06, 2018 4:41 pm
by CZFan
I think your firewall rules can be improved upon, i.e. your very first 2 rules are incorrect and will never work as expected, they are the wrong way around.

Also try making use of fasttrack in firewall to reduce CPU usage

Re: High CPU usage.

Posted: Fri Apr 06, 2018 4:49 pm
by BartoszP
Or disable rule #7 to check if usage will drop? There are lots of packets "firing" this rule.

Re: High CPU usage.

Posted: Fri Apr 06, 2018 8:30 pm
by blajah
Do you have default deny rule in input chain? What is in your connection tracking table? Sources you added to address list, you can drop in RAW firewall.

Re: High CPU usage.

Posted: Sat Apr 07, 2018 9:46 am
by aacable
in one case I found a script that was running continuously caused high cpu usage.

Re: High CPU usage.

Posted: Sat Apr 07, 2018 11:50 am
by mistry7
Help to deal with the problem of high load (up to 100%) of the processor on the CRS112-8G-4S.
There are up to 10 pppoe customers.

You Choose a frong device for this job,
How fast is your Upstream connection?

Re: High CPU usage.

Posted: Sun Apr 08, 2018 7:31 pm
by erlan
I think your firewall rules can be improved upon, i.e. your very first 2 rules are incorrect and will never work as expected, they are the wrong way around.
Or disable rule #7 to check if usage will drop? There are lots of packets "firing" this rule.
I already dasbled all the rules, but it did not give a positive result
in one case I found a script that was running continuously caused high cpu usage.
Tell me which one?
You Choose a frong device for this job,
How fast is your Upstream connection?
15Mb/s

Re: High CPU usage.

Posted: Sun Apr 08, 2018 10:57 pm
by raidu
Sorry, but this device is not meant to handle any tunneling and the CPU load you are experiencing is normal.
The CRS112-8G-4S is a routing capable switch, where the routing function is mainly for management purposes.

The cheapest MT device that would handle some tunneling is the RB750Gr3 ie. HEX

Re: High CPU usage.

Posted: Mon Apr 09, 2018 1:16 pm
by Steveocee
I regularly see CRS112's hitting 100% on the CPU just from an SNMP call. I even see my one at home doing 80% just from viewing it in Winbox. Others have pointed out optimisations for you but you should probably invest and replace the device with either an RB2011 or RB3011.

Re: High CPU usage.

Posted: Thu Apr 12, 2018 12:11 am
by poizzon
https://youtu.be/3LmQYIQ5RoA?t=843

Sometimes the situation is not going to happen to you?

Re: High CPU usage.

Posted: Thu Feb 14, 2019 8:54 pm
by Cartman
OK, I know the thread is a bit older, nut I have the same problem.
Already took a RB2011 for routing and load balancing and let
the crs112 do the switching, but isĀ“nt there a device that does
it all?
What about the CRS328-24P ? It is a bit bigger, but that shoud not
be a problem as long as it can do the routing without reaching
its limits.
I need a device that can do load balancing for two WANs and
switching for 6 connected devices (now Groove, might change).
AND: It has to provide power for the connected device. There are
not too many RBs with such many PoE-outs.
The CRS328 also has only one CPU, would that be enough ?

Thanks for your replies.
Wayne

Re: High CPU usage.

Posted: Thu Feb 14, 2019 9:06 pm
by Dude2048
Buy a ccr.