Created attachment 1657023 [details] Output of journalctl --no-hostname -b -2 -k > dmesg.txt 1. Please describe the problem: RX errors of around 3% when using the latest kernel on wired Ethernet with the above NIC. 2. What is the Version-Release number of the kernel: kernel-5.4.14-200.fc31.x86_64 3. Did it work previously in Fedora? If so, what kernel version did the issue *first* appear? Old kernels are available for download at https://koji.fedoraproject.org/koji/packageinfo?packageID=8 : Worked correctly on previous versions, latest being kernel-core-5.4.13-201.fc31.x86_64 4. Can you reproduce this issue? If so, please provide the steps to reproduce the issue below: Run a speedtest (e.g. at speedtest.net) and observe dramatically lower download bandwidth. Run ifconfig to observe RX errors field for the NIC at about 3% of RX packets. Router, cabling etc. unchanged between tests. 5. Does this problem occur with the latest Rawhide kernel? To install the Rawhide kernel, run ``sudo dnf install fedora-repos-rawhide`` followed by ``sudo dnf update --enablerepo=rawhide kernel``: N/A 6. Are you running any modules that not shipped with directly Fedora's kernel?: No 7. Please attach the kernel logs. You can get the complete kernel log for a boot with ``journalctl --no-hostname -k > dmesg.txt``. If the issue occurred on a previous boot, use the journalctl ``-b`` flag.
After update to kernel 5.4.15-200 the problem has disappeared.
(In reply to Patrick O'Callaghan from comment #1) > After update to kernel 5.4.15-200 the problem has disappeared. No, it's still there. My mistake.
Considering the possibility of a hardware fault. Changing the Ethernet cable (which I had done before in testing) now seems to correct the problem. It could also be a flaky NIC but I don't have a spare one to test.