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With CSF (Firewall) active the port bandwidth (Mbps) drops drastically



  • quietFinn

    I was testing this in an OVH public cloud server, 2 vCores, 8 GB RAM, 500 Mbps public bandwidth, AlmaLinux 8.9, cPanel 116.0.6, and speedtest gives the same results when CSF is ON and OFF.

    Idle Latency:     4.74 ms   (jitter: 0.15ms, low: 4.58ms, high: 4.90ms)
        Download:   488.06 Mbps (data used: 232.8 MB)
                     69.53 ms   (jitter: 9.55ms, low: 5.08ms, high: 119.93ms)
          Upload:   489.94 Mbps (data used: 221.4 MB)
                     69.15 ms   (jitter: 9.34ms, low: 4.61ms, high: 116.79ms)
     Packet Loss:     0.0%

    CSF ON
    idle Latency:     4.78 ms   (jitter: 0.06ms, low: 4.72ms, high: 4.84ms)
        Download:   488.21 Mbps (data used: 238.4 MB)
                     73.42 ms   (jitter: 13.17ms, low: 4.81ms, high: 207.99ms)
          Upload:   488.34 Mbps (data used: 219.3 MB)
                     72.51 ms   (jitter: 18.47ms, low: 4.56ms, high: 209.30ms)
     Packet Loss: Not available.

  • cPRex Jurassic Moderator

    I've never heard of CSF limiting to this level, but this would be something to reach out to their team about at as this isn't a cPanel product.

  • ruyman


    Thanks for taking the time to check it out. I also have the same versions that you tell me about on the VPS, CSF (14.20). I see that in your case there are no problems.

    I have also tried it on my personal computer, making a virtual machine with a clean Almalinux8.6 (with virtualbox), I see that it also limits but in a different way.

    I'll try to submit a ticket to CSF and see what they say.



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