Possible performance limitations?



  • So I have pfSense installed on a bookshelf PC at home, with a dual core w/ HT Atom.  It has dual Gb onboard NICs, and has been a great stable platform for pfSense for me for years now.  So I've been a little behind the times, and have only recently realized that Comcast has given me a free upgrade in speed to ~100Mbps–up from the ~20 or so that I originally purchased from them years back.  However, in doing speed tests, I'm only seeing ~32Mbps down, & ~8Mbps up.

    I would like to troubleshoot this on my own first before bringing in Comcast CS, because whenever I do, they invariably find a way to screw up my account, and it takes weeks to get things back to the way they were.  So normally I would just bypass pfSense to ensure that it's not the culprit, but it appears that they do MAC filtering, which is a pain to get around.  So my question to you all is, how can I determine if pfSense is limiting my connection or not?  I would assume that speed would be limited primarily by CPU on pfSense.  But during my speed tests, I run top on the shell, and I don't see load go above .22.  Can anyone give me any pointers on what I can check on pfSense to rule it out?

    Some additional info:
    -I have no traffic shapers defined
    -The connection info that the dashboard shows is that I am connected at 1000baseT full-duplex,master to my modem
    -Modem is my own (not rented from Comcast), Motorola SB6121
    -Firmware on modem suggests they do periodically update my modem's firmware, it has a build date of Feb 2016
    -When I do the speed tests, it shoots right up to 32Mbps, not a gradual climb, indicating to me that it seems to have no troubles with that speed.



  • This should be posted in one of the Support forums such as General Questions.

    but it appears that they do MAC filtering, which is a pain to get around

    Normally a reboot of the cable modem clears that.


  • Rebel Alliance Global Moderator

    When was the last time you reboot your modem?  When they up your tier you have to reboot.  If you change the device connected to the modem - again you have to reboot.  While yes the modem caches the mac that its talking to.. Your pc, pfsense nic, some other router, etc..  Reboot of the modem clears that.

    Over the years I have moved tiers with comcast.  And you have to reboot the modem to see the new speed..



  • Try logging into your modem to find out how it's connection. It should tell you all kinds of data, like DOCSIS 2.0 or 3.0, how many channels are being bonded, if any. etc etc 32Mb/s is almost spot on a single channel, which makes me wonder if bonding is not working.



  • Modem was rebooted today as part of my troubleshooting.  Speeds didn't change.

    I've visited my modems status page on several occasions, got the firmware version there.  I attached a screenshot of my modem signal settings.  From what I see, it looks like bonding is working.




  • My reading comprehension isn't always the best, but I don't think you mentioned if you attempted to bypass PFSense and speedtest directly to the modem.



  • He can't because his access is tied to the MAC address of his pfSense WAN.  He needs to clear his cable modem and then direct connect his PC to it and test again to make sure he is getting what he's supposed to.  Once confirmed, then he can reconnect pfSense and start troubleshooting.



  • I haven't had a chance to do any troubleshooting today, but I should have some time tomorrow to try resetting the modem and plugging a PC directly in to do speedtest, bypassing pfSense.

    If those speeds don't change, does it still look like maybe there's something wrong with the bonding?  I would have expected that the signal settings I pasted earlier showed that bonding was indeed occurring with 4 channels, but perhaps I am mistaken.



  • It does look bonded according to the status page and nothing seemed crazy for the errors either. Instead of resetting your modem, you could clone your WAN's MAC address.



  • OK, so I just went ahead and spoofed the pfsense's mac address on my windows pc, and was able to get directly onto the internet.  I went to speed test.net, and did the same test–precisely the same numbers as before.  So pfSense is definitely not the limiting factor... both yay, and boo.  I guess that means a call to Comcast...  @#$%$#!



  • Huzzah!  Apparently the "issue" was that my modem wasn't registered with them, so they put it on some kind of generic configuration (I'm not sure why it wasn't registered previously, I had to give them all the info before when I first got it).  The registration went through, and they reset my modem, and now I'm getting 90Mbps down & 12Mbps up (which is more than what my account says I should have–75Mbps down & 10Mbps up).  And most importantly, pfSense didn't even hiccup with these speeds! :)