UTorrent causing services restart every 1-2 minutes

  • Dear fellows,

    I was trouble shooting for a while a specific problem with my WAN interface receiving SIGHUP and dropping the internet connection frequently. I confirmed, that the problem is not in my ISP, but somewhere in my pfsense configuration.

    Last night the defect became very obvious, every 1-2 minutes the connection was dropping. After some trouble shooting I found, that when uTorrent is active, pfsense box restarts it's services every 1-2 minutes, causing internet to drop. My WAN is configured in PPPoE mode via ethernet cable to my provider (no modem in between).

    When I turn off uTorrent - the connection is stable, no drops.

    Do you have any idea why this is happening and how uTorrent is messing up with my pfsense box? I'm happy to provide additional details if needed.

    I'm looking forward to hearing from you.


  • Banned

    Yeah, when you kill your connectivity with P2P crap to the point that ping to your WAN gateway takes ages or even no longer works, WAN goes down. You can tweak or disable the GW monitoring, but preferably you'd set up some traffic shaping and limit your torrents to something sane.

  • Hi doktornotor,

    Thanks for your reply. I forgot to mention that the symptoms are present even when all uTorrent jobs are stopped (no download/upload). That is why I'm confused. If there were active jobs, I would have guessed that I was running out of states, but that is not the case.

    The highest ping time I get, when the problem is obvious is 8-9 ms. The wan ping is fine. Please have a look in the attachment.


  • Banned

    If you actually look at the graph, there are periods of complete drop out. Pretty frequent ones. Cannot see how's that "fine". Also, cannot see how are you pinging anything on WAN when you just told use that your WAN goes down and drops internet connectivity (which, again, is pretty visible on the graphs).

  • Hi doktornotor,

    Thanks for the activity.

    You're absolutely right in what you're saying, I didn't express myself very clear.

    From the graph I can see that the highest delay is around 8ms. If WAN interface is flooded with too many simultaneous connections I would expect higher delays before dropping the connection (>100ms), that's what I meant under "fine" - just 8ms.

    However the problem is when the uTorrent is running idle (no active connections from/to uTorrent). It's doing something that's causing pfsense to restart all services. How can I detect what exactly is causing the serices restart?


  • Banned

    Those zillions of connections? It just does not work the way you think. There are tons of connections even when you are not downloading/uploading anything. Just look at the firewall states. Other than that, hints already given above.

  • Can you post your bandwidth graph for the exact same time period as your quality graph?

  • Hi Harvy66,

    Thanks for your reply, I've attached the traffic graph:

  • I experienced a similar issue several years ago.  Turns out my pfSense box was undersized.

    What is your state table size/usage, MBUF size/usage, CPU and RAM usage?

    See if there is a correlation between the gaps in your bandwidth chart and the other system vitals.  I have a hunch you're running out of resources somewhere.

  • Hi Tim,

    My hardware is:

    Motherboard: GIGABYTE GA-C1037UN-EU (Intel® Dual-core Celeron® 1037U processor (1.8 GHz))
    RAM: KINGSTON 2GB DDR3 1600 HYPER X (Part Number: KHX1600C9D3B1K2)
    SSD/DOM: 16GB Apacer SDM4-M APSDM016G15AN-CCM 22pin 90° Industrial S-ATA DOM

    pfSense installed: 2.2.2 (amd64)


  • Thanks for posting your specs.

    However, can you take a look at the metrics I listed above and see if there is a correlation between resource utilization (CPU, RAM, MBUF, etc.) during the outages.

    Also, in the system.log are there events occurring during these events that are getting logged?

  • I had the same problem before I adjusted the Gateway Monitoring with more relaxed setting for detecting delay. By default it pings every second. Since I have ftth and not copper dsl I figured I wont face line quality issues. Connection is either up or down. The pppoe connection has been stable for weeks.

    System: Gateways: Edit gateway (WAN)
    Latency thresholds 700-999
    Packet Loss thresholds 80-95
    Probe Interval 10
    Down 50
    Average Delay Replies Qty 20
    Average Packet Loss Probes & Qty Lost Probe Delay - Use calculated value

  • @tim.mcmanus:

    Thanks for posting your specs.

    However, can you take a look at the metrics I listed above and see if there is a correlation between resource utilization (CPU, RAM, MBUF, etc.) during the outages.

    Also, in the system.log are there events occurring during these events that are getting logged?

    Hi Tim,

    Thanks for your reply. I made a screenshots of all the data you've mentioned above. Please have a look in the attachment:

  • Today I did an experiment. uTorrent downloading/uploading for 7-8 hours - no problems in terms of service availability. Not a single pfsense service restart.

    As soon as I stopped everything and left the uTorrent in idle mode - pfsense started restarting the services every minute or so.

    Shortly - when the uTorrent is working - no problems, but as soon as it goes in idle - problem reoccurs.

    Any ideas why?


  • Just a wild shot: do you use - and is there any uPNP activiy ?

  • Hi Gertjan,

    Yes, I confirm there is uPNP activity on my Network (My Samsung TV is using UPNP, my Netgear access point is advertising UPNP etc.), however UPnP & NAT-PMP are disabled in pfsense. How is that affecting the drops? I've noticed, that uTorrent has several UPNP options active (please check the attachment) as well.


    ![uTorrent Config.jpg](/public/imported_attachments/1/uTorrent Config.jpg)
    ![uTorrent Config.jpg_thumb](/public/imported_attachments/1/uTorrent Config.jpg_thumb)

  • Hi fellows,

    I found some correlation between uTorrent settings and pfsense.

    When I disable the setting "Enable DHT Network" under Options/Preferences/BitTorrent in uTorrent, the problem goes away, but as soon as I enable it - WAN gateway restarts every 1-2 minutes.

    Any ideas how this setting is affecting pfsense?


  • Banned

    This setting, as already said above, causes uT to establish hundreds/thousands of peer connections, regardless of whether you are transferring any files or not. See DHT Protocol.

  • Thanks a lot. Hopefully the problem is solved now.

    It's pity, that uTorrent has this setting enabled by default.


  • Why is it a pity? It makes BitTorrent better. I have no issues with it. Have you tried plugging directly into your port to see if the problem persists without PFSense in the mix?

  • Banned

    I run Utorrent on a seedbox and no issues with restarts.

    I run 2.1.5 in front of the box. Hasnt upgraded to 2.2.2 yet.

    Wonder if this could be related to the SYN ACK issue described elsewhere. When DDoS'ed the only thats in the logs, is a WAN restart within seconds of the box dyiung on me.

  • I'm using 2.2, no issues. One of these days I'll upgrade. But then 2.2.3 will come out right after, right?  ::)

  • Banned

    I think 2.2.3 is not long now…

  • Hi guys,

    I'm pleased to see that much activity :) Thank you!

    Actually, when DHT is enabled and I'm actively seeding, there is no problem, but as soon as uTorrent goes in idle (all torrents stopped, but uTorrent application still running), all pfsense services restarts.

    My WAN interface is configured in PPPoE mode and there is no modem in between - direct UTP cable to my ISPs neighborhood distribution point. My internet connection is 80 Mbit/s symmetrical line, quite pleased with it.

    However I'll leave DHT disabled and continue monitoring my pfsense box.

    @Supermule, can you please extend you thoughts on the SYN ACK issue and DDoS, because I would like to read some more info on the topic. Thanks.


  • It's possible that the PPPoE server can't handle that many connections.

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