What does “UPnP/NAT-PMP: Port mapping failure” mean in qBittorrent


There is an error UPnP/NAT-PMP: Port mapping failure, message: could not map port using UPnP: no router found (always appears thrice with the same timestamp) in execution log (view > log > show). No other errors. The message appears when the client connects. I haven't noticed any speed or connection issues, however.
qBittorrent 3.3.12.

Best Answer

  • If you are not facing any issues you can safely ignore this message. As can be seen here.

    UPnP/NAT-PMP is used here to Forward/Open ports in an upstream router to provide a connection to your machine from outside.

    This port-forwarding can fail in following scenarios:

    1. Upstream router does not support UPnP/NAT-PMP
    2. UPnP/NAT-PMP is disabled on upstream router.
    3. No upstream router. (You are directly connected to Internet)

    Port-forwarding can succeed but still in fail in following scenario:

    1. Double-NAT/Multiple-NAT. First level up supports UPnP/NAT-PMP but further routers do not Port-Forward to you.