PacketRouting High CPU

[jmidd]

In the past couple of weeks, our 3430 has started having high CPU usage during the day.  Sometimes it is high enough that we have to reboot the router to get it to work properly again and are barely able to SSH into to get that done.  The only change we can think of that has happened in that time is that our internet connection has increased from 10Mb to 50Mb.  And it is always the PacketRouting process that is using up the CPU cycles.  We disabled IP Monitoring and it is still happening.

I have attached our router config.

[Anonymous · Accepted solution]

You are running NAT and IPSEC on your router.  That produces heavier CPU load as bandwidth usage increases.  The effective throughput of the 3430 with VPN features enabled is about 30mbps.  And that is aggregate, so if you are pulling (for example) 25 down and loading 10 up, you are definitely going to run into CPU issues.

With the VPN features, you may want to look at getting a 3140.  It is very cost effective and supports a much higher throughput with features enabled.

[jmidd]

We were afraid that might be it.  If we remove the VPN usage, would that make enough difference or would NAT alone still use too many CPU cycles at 50Mb?

[Anonymous]

It should help to remove the IPSec functions (you should reboot after clearing out the config), but obviously you will be handicapping your network in some way by doing so.  If you are still running FW/Nat functions, supposedly it can still support 100mb of throughput.  If you are using traffic shaping.or QOS policies, then the number is 50mbps.

I am not a salesman, but I recently started deploying 3140's because of their ability handle larger bandwidth usage.  They are really cost effective and given your setup on a 3430, it would probably drop in place for you easily. 

You can review router features and capabilities with this tool: AOS Feature Matrix - Product Feature Matrix