Fortinet Fortigate Internet Traffic Halts – CPU At 99%

Ran into a wonderful situation yesterday on a Fortinet Fortigate 100C where, every hour on the half hour the internet traffic would cease passing through the router.

The solution was to reboot the firewall.

Turns out, there was a bug in the 4.2 firmware (4.0 build 0272) with the NIDS signature. I believe it was triggered when our Trend Micro Worry Free Business Security Advanced server would try to update (hence the every hour on the half hour).

This was diagnosed via the CLI command:

Diag Sys Top 1

Let that run for a few seconds, then hit CTRL-C to stop.

IPSEngine was using 90+ % CPU (the first decimal number in the 2nd to last column is CPU usage, the last is memory usage)

Fortinet support sent me the newer NIDS signature manually, which should be automatic later today.

Fun times.

3 Replies to “Fortinet Fortigate Internet Traffic Halts – CPU At 99%”

  1. Hello,

    I have a Fortigate 3810A running 4.0 MR3 Patch 10.

    Documentation says i have 4 CPUs but only CPU3 is ‘working’.

    FW(global) # get system performance status
    CPU states: 3% user 26% system 0% nice 71% idle
    CPU0 states: 4% user 3% system 0% nice 93% idle
    CPU1 states: 8% user 3% system 0% nice 89% idle
    CPU2 states: 1% user 0% system 0% nice 99% idle
    CPU3 states: 0% user 97% system 0% nice 3% idle

    Why are the other 3 CPUs not used?

    Do you have any idea why my CPU hits 100% on CPU3?

    Can i share the load across all CPUs?

    Kindly advice.

    Thank you

  2. David,

    Wish I could help but I don’t have any experience with that unit.

    Best I could suggest would be the user forum (which I haven’t been on in a while because it didn’t seem active and helpful) or contact support.

    Fortinet keeps winning awards, their stock price goes up, but support sure isn’t what it was in the old days.


Leave a Reply

Your email address will not be published. Required fields are marked *