Interface Errors

  • My logs are showing Interface "Errors Out" entries (see attached image) and I am not sure how to correct them. The network works fine but seeing the errors is distracting.

    The LAN interface is a bridge and only shows errors when I undock my laptop from the docking station (connected via ethernet to the pfSense box).

    I am guessing that the errors are a result of the ethernet cable connecting pfSense to an empty docking station.

    Any ideas about what I can do to correct these Interface "Errors Out" log entries?

    Thank you.


    Original Thread (old)
    Re: [Solved] In/out errors on LAN

  • Put a switch between the dock and the router. Or just ignore them since you know whats causing them.

  • No other option besides adding hardware?

  • Not that Im aware of but maybe someone has a way to disable that particular line on your graph..

    Its reporting what it see's. My modem uses two bonded ethernet cables and it will report a few errors when I first restart everything when I do at times.. I know what causes it so no worries.

  • Ok, maybe someone will chime in with another suggestion:) But, thank you very much for the fast responses!

  • Netgate Administrator

    Try re-assigning the interface to a different NIC see if follows that. Unless it's actually the bridge interface of course.

    Though if it is the bridge interface what is in the bridge? A wifi interface? That will almost always have errors.


  • @stephenw10 The same "Errors Out" entries appear irrespective of NIC. So, I think the NICs in the bridge are fine. The bridge has three interfaces (all wired ports on a 4 port switch).

  • @netgate2020 said in Interface Errors:

    The LAN interface is a bridge and only shows errors when I undock my laptop from the docking station

    The bridge has three interfaces (all wired ports on a 4 port switch).

    This may be just one reason that many here recommend against bridging interfaces and using that method as a switch. I for one did so for a couple of VOIP ATA's and can say that when one of the ATA's got rebooted the errors would always happen.

    I might suggest that you put that particular interface on its own subnet.

  • Netgate Administrator

    @netgate2020 said in Interface Errors:

    The bridge has three interfaces (all wired ports on a 4 port switch).

    Not sure if I understand this correctly... you have three NICs in the bridge in pfSense and they are all connected to the same 4 port switch? That make very little sense!


  • @stephenw10 The setup is as follows:

    port1 = WAN (cable modem)
    port2, port3, port4 are bridged

    Is my setup incorrect and/or odd?

    Thank you again for your thoughts and feedback.

    interface assignments.png

  • Netgate Administrator

    That looks OK, if you really need to use a bridge. The confusing part is that you said:

    The bridge has three interfaces (all wired ports on a 4 port switch).

    Those ports, igb2,3 and 4, are connected to the same switch externally?


  • @stephenw10 The bridge has three internal interfaces and the external devices connected are a docking station, a desktop pc, and a wi-fi access point. I apologize for not starting this thread with a clearer description of the equipment setup. Thank you for asking these questions.

  • Netgate Administrator

    Ah, OK so the bridge is acting as a switch here.

    Generally using an actual switch will be better here. A bridge is not a switch.

    There are some advanced options on the bridge you can play with. I'm not aware of any specifically that would cause output errors like that.

    If you're not seeing any actual connectivity issues I would just live with it for now.


  • @stephenw10 Ok, will do, thank you. Is there any performance or other negative impacts associated with having the "Errors Out" occurring while the laptop is disconnected from the docking station?

  • Netgate Administrator

    Ah, I may have lost sight of the big picture here! Do you only see the error accumulate when you remove the laptop? Or for sometime after the laptop has been removed?

    The bridge will learn which port a connected MAC is on and will try to use that. pfSense will have your laptops MAC in the ARP table when it's removed so any traffic destined for it I could imagine showing an error there.
    Or I could imagine the dock connector drops some connections as it's pulled causing some errors.

    It's unlikely that cause an issue for anything else on the bridge. Bridges are not high performance anyway though. Use a real switch if you're looking for best performance.


  • @stephenw10 Correct - the errors accumulate after removing the laptop from the docking station. The laptop connects via wi-fi after being removed from the dock (the dock is connected via Ethernet).

    I like your theories. Is using Diagnostics --> Packet Capture a viable way to continue investigating?

  • Netgate Administrator

    Hmm, well you could try a pcap on the bridge interface but the fact it's showing output errors implies it's unable to send so you may not see those packets.

    You could try reducing the cache time in the bridge advanced settings. Though this is something much shorter than that.


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