I had the same problem with Kernel 5.8.0-41. All Kernel after that had no LAN INternet.
I solved it today. As I installed two packages I dont know which one solved the issue. First I installed sudo apt install ntp ifupdown (a hint from a forum regarding this issue) Then I re-installed sudo apt install --reinstall linux-modules- extra-5.8.0-44* Either one of that or mybe both are the solution of the problem for me. Hope that helps. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1906655 Title: Ethernet interface broken (Flags mismatch irq) after upgrading to kernel 5.8.0-31 Status in linux package in Ubuntu: Confirmed Bug description: Realtek ethernet network interface is broken when booting with kernel 5.8.0-31. It works fine when simply booting with previous kernel 5.8.0-29 in GRUB. No other packages were updated. The only related line in /var/log/kern.log: Dec 3 14:01:21 hd kernel: [ 17.824691] genirq: Flags mismatch irq 16. 00010080 (enp4s0) vs. 00002080 (uhci_hcd:usb3) `lspci -v` for this network interface below (`lspci -vv` attached): 04:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 01) Subsystem: Gigabyte Technology Co., Ltd Onboard Ethernet Flags: bus master, fast devsel, latency 0, IRQ 16 I/O ports at d000 [size=256] Memory at f8000000 (64-bit, non-prefetchable) [size=4K] Expansion ROM at f7000000 [virtual] [disabled] [size=128K] Capabilities: [40] Power Management version 2 Capabilities: [48] Vital Product Data Capabilities: [50] MSI: Enable- Count=1/2 Maskable- 64bit+ Capabilities: [60] Express Endpoint, MSI 00 Capabilities: [84] Vendor Specific Information: Len=4c <?> Capabilities: [100] Advanced Error Reporting Capabilities: [12c] Virtual Channel Capabilities: [148] Device Serial Number 00-00-00-00-10-ec-81-68 Capabilities: [154] Power Budgeting <?> Kernel driver in use: r8169 Kernel modules: r8169 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1906655/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
