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    Snort Inline IPS Speeds

    Scheduled Pinned Locked Moved General pfSense Questions
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    • D
      droidus
      last edited by

      I was running snort inline ips. I understand that it affects my speeds. But I didn't know it was this bad. I am using verizon fios, and get speeds as follows:
      5ae8d389-4f6a-4d1b-865a-6c305eb14309-image.png
      This is when I am NOT running snort on my device.
      When running Snort, I get about 10/10. Is this normal? I don't believe I went crazy with the rulesets....
      I am using a IP reputation list.

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      • bmeeksB
        bmeeks
        last edited by bmeeks

        You omitted some needed information such as what exact type of hardware is pfSense running on and how much RAM is available? Snort is single-threaded and thus works best with very high clock speed CPUs. With Snort, it's the CPU clock speed that matters most and not the number of cores as only a single core will ever be used by Snort.

        Typically I would expect throughput speed with IPS enabled to be 75% to as low as 50% of the speed you get with IPS disabled. But that all really depends on the enabled rules. And it's not just the number of enabled rules. What those rules are doing matters as well. Some rules can be computationally intense with pattern matching. You mention IP reputation list rules. Those will be the least computationally intense.

        Your throughput should definitely be better than 10/10 (I assume you mean megabits/second with those values) unless you have truly anemic hardware.

        D 1 Reply Last reply Reply Quote 0
        • D
          droidus @bmeeks
          last edited by

          @bmeeks
          It is the Protectli FW4B - 4 Port Intel® J3160. I have 8 GB RAM total.

          bmeeksB 1 Reply Last reply Reply Quote 0
          • bmeeksB
            bmeeks @droidus
            last edited by bmeeks

            @droidus said in Snort Inline IPS Speeds:

            @bmeeks
            It is the Protectli FW4B - 4 Port Intel® J3160. I have 8 GB RAM total.

            That hardware should easily do much better than the 10/10 you said you are seeing.

            I can already guess your next question, but sorry, "no, I have no idea why you are not seeing better performance" ... 😀. That slow throughput is certainly not the case with many other users here on similar types of hardware in terms of capability. You will likely never get line-rate Gigabit traffic inspection with Snort unless you have a screaming fast CPU, but you should get better than 200 Mbps with most hardware.

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