Packet loss shown in RRD graphs



  • Sometimes I see this as high as 4% average over the course of the day.

    I saw this report http://www.dslreports.com/faq/14068

    If you are also seeing packet loss from these points all the way to the final hop of your test, that points to a problem on the device first showing packet loss or on the inbound connection to that device.

    However, if you are not seeing packet loss all the way to the final hop, this apparent packet loss may not be an issue.

    Some providers are rate-limiting how often they respond with the TTL-exceeded ICMP packets used by traceroute and similar tools like the Packet Loss Test. This is done to prevent attacks against these routers, since responding to these packets requires much more CPU time than simply forwarding the packet does. If the router is set up to rate-limit, it will respond to a certain number of traceroute packets per second, and once that many have been received, it will stop responding to them for that second – which will appear as packet loss. You are not losing any "real" traffic, assuming the final hop of your traceroute isn't showing any loss.

    and before I go and complain to my ISP, i'd like some more facts on exactly how PFsense is determining packet loss that is displayed in the RRD graphs. Is this just a random ping to the gateway? monitoring all my traffic? etc? What facts do I need to present to my ISP? Just the fact that there is packet loss?


  • Rebel Alliance Developer Netgate

    It pings your gateway once per second, or an alternate monitor IP if you have one configured.

    If your gateway is your local modem and you're seeing loss, it could be the modem itself or the Ethernet cable, or even the NIC on pfSense.

    If your gateway is farther out than that (e.g. across your DSL/Cable/etc line) then the loss could be there also.



  • If you're seeing the 4% loss continuously throughout the day, then you're probably seeing a common issue with the apinger service. If it only shows up during part of the day, then you should search dslreports for their smokeping service to collect more evidence.

    If it is continuously reporting 4%, then see this:
    http://forum.pfsense.org/index.php/topic,68637.0.html

    The RRD quality graphs get their data from the apinger service. The workaround to the continuously bogus loss issue is to restart apinger.

    Try going to status->services and restart apinger. See if that resets the reported losses to around 0. Just the other day I saw a bogus 4% loss too. Restarting the service fixed that.



  • @darkcrucible:

    If you're seeing the 4% loss continuously throughout the day, then you're probably seeing a common issue with the apinger service. If it only shows up during part of the day, then you should search dslreports for their smokeping service to collect more evidence.

    If it is continuously reporting 4%, then see this:
    http://forum.pfsense.org/index.php/topic,68637.0.html

    The RRD quality graphs get their data from the apinger service. The workaround to the continuously bogus loss issue is to restart apinger.

    Try going to status->services and restart apinger. See if that resets the reported losses to around 0. Just the other day I saw a bogus 4% loss too. Restarting the service fixed that.

    restarting apinger worked for me… thanks!! will keep monitoring to see if the problem comes back...


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