A single computer is throttled in the upload

Hello all.

I'm getting a little desperate right now. Since today a computer in the network (VLAN1) is throttled during upload to only 1mbit or less. Normally it should get 40Mbit to the internet. The download works fine. It is connected via a LAN cable. The computer was checked without UTM in between, it also creates the 40Mbit. If I connect the computer via WiFi to the UTM (other VLAN2) it works fine. No other computer has the problem in this VLAN1.
If I route the same computer via another UTM in the network (VLAN3) via NAT into VLAN1, I also have no problems.

Neither IPS nor QOS is switched on. In the meantime I have deactivated almost everything. Has anyone ever seen such a problem.

Thanks in advance and greetings

  • Hello Marcel,

    could be different settings on the second UTM in regard to handle "invalid packets".

    Or a problem with the LAN driver and/or the hardware. I had very strange issues with MTU-size, so maybe just try this out, for example reduce MTU on that station to 1320 bytes..

    Mit freundlichem Gruß, Regards from Germany,

    Philipp Rusch

    New Vision GmbH, Germany
    Sophos Silver-Partner

    If a post solves your question please use the 'Verify Answer' button.

  • Under Interfaces and Routing -> QoS -> Download throttling: check if there are rules configured that do this. Make sure to check both the VLAN1 interface and the WAN interface where you see this happening.

    Managing several Sophos UTMs and Sophos XGs both at work and at some home locations, dedicated to continuously improve IT-security and feeling well helping others with their IT-security challenges.

    Sometimes I post some useful tips on my blog, see blog.pijnappels.eu/category/sophos/ for Sophos related posts.

  • Hallo Philipp,

    was ich daran nicht verstehe, es haben keine anderen Systeme an der Schnittstelle der UTM dieses Problem. 
    Der Rechner hatte bis vorgestern auch kein Problem, hab daran auch nichts geänder (Standard Spruch (ich weis)) 
    Die zweite UTM habe ich nur ausprobiert um zu schauen ob die Schnittstelle vom PC in ordnung ist. 
    Ich habe schon viele UTMs in Betreib genommen und betreibe auch einige in der Firma, aber das was hier passiert ist mir wirklich unerklärlich.

    Das herabsetzten der MTU hatte leider keinen Erfolg. Treiber sind soweit auf dem aktuellen Stand. 
    QOS ist nicht eingeschaltet auch sonst ist keine Begrenzung aktiv. Auch IPS ist aus. 

    Noch irgendeine Idee?


  • Hi, QOS is disabled.
    and no other rule for throttling is enabled. 

  • Hallo Marcel and welcome to the UTM Community!

    Do you learn anything by doing #1 in Rulz (last updated 2020-11-12)?

    Also, tell us what you see that makes you conclude that "QOS is disabled."

    Cheers - Bob

    Sophos UTM Community Moderator
    Sophos Certified Architect - UTM
    Sophos Certified Engineer - XG
    Gold Solution Partner since 2005
    MediaSoft, Inc. USA