No LAN connection when LAN cable plugged in

I wanted to connect my laptop with a cable. I expected the system to switch to cable connection automatically when cable was plugged in. It didn’t happen.

I am running Plasma KDE. After plugging cable, there is no LAN connection on connections list. I checked on my router and the proper LAN lamp is active when the cable is connected. I checked a different cable and it correctly detects and turns the LAN light on, so it seems that both cable works fine and that router detects connection with the laptop.

I followed some old Arch advice and checked:

sudo systemctl status dhcpcd.service

It was inactive, so I enabled and started it. Just to be sure, I rebooted the system. Checked status again and now it shows that it is active.

Still, no LAN connection on Connections list in system tray. So what is going on? How to check what is missing and why I am not connecting by cable?

inxi -b
System:
  Host: Sirius16-Manjaro Kernel: 6.14.7-1-MANJARO arch: x86_64 bits: 64
  Desktop: KDE Plasma v: 6.3.5 Distro: Manjaro Linux
Machine:
  Type: Laptop System: TUXEDO product: TUXEDO Sirius 16 Gen1 v: N/A
    serial: <superuser required>
  Mobo: NB04 model: APX958 serial: <superuser required> UEFI: American
    Megatrends LLC. v: 1.00A00_20240108 date: 01/08/2024
Battery:
  ID-1: BAT0 charge: 79.3 Wh (99.0%) condition: 80.1/80.1 Wh (100.0%)
CPU:
  Info: 8-core AMD Ryzen 7 7840HS w/ Radeon 780M Graphics [MT MCP]
    speed (MHz): avg: 2395 min/max: 400/5137
Graphics:
  Device-1: Advanced Micro Devices [AMD/ATI] Navi 33 [Radeon RX 7600/7600
    XT/7600M XT/7600S/7700S / PRO W7600] driver: amdgpu v: kernel
  Device-2: Advanced Micro Devices [AMD/ATI] Phoenix1 driver: amdgpu
    v: kernel
  Display: wayland server: X.org v: 1.21.1.16 with: Xwayland v: 24.1.6
    compositor: kwin_wayland driver: X: loaded: amdgpu
    unloaded: modesetting,radeon dri: radeonsi gpu: amdgpu
    resolution: 2560x1440~165Hz
  API: OpenGL v: 4.6 compat-v: 4.5 vendor: amd mesa v: 25.0.5-arch1.1
    renderer: AMD Radeon 780M (radeonsi phoenix LLVM 19.1.7 DRM 3.61
    6.14.7-1-MANJARO)
  Info: Tools: api: clinfo, eglinfo, glxinfo, vulkaninfo
    de: kscreen-console,kscreen-doctor wl: wayland-info,wlr-randr
    x11: xdpyinfo, xprop, xrandr
Network:
  Device-1: Realtek RTL8111/8168/8211/8411 PCI Express Gigabit Ethernet
    driver: N/A
  Device-2: Intel Wi-Fi 6E AX210/AX1675 2x2 [Typhoon Peak] driver: iwlwifi
Drives:
  Local Storage: total: 2.73 TiB used: 1.13 TiB (41.3%)
Info:
  Memory: total: 32 GiB note: est. available: 30.57 GiB used: 7.02 GiB (23.0%)
  Processes: 447 Uptime: 24m Shell: Bash inxi: 3.3.38

There is no driver for your Ethernet card:

Don’t know why.
Is it perhaps blacklisted?

Can you provide
inxi -zv8
for more detail on that device?

inxi -zv8
Network:
  Device-1: Realtek RTL8111/8168/8211/8411 PCI Express Gigabit Ethernet
    driver: N/A modules: r8169 pcie: gen: 1 speed: 2.5 GT/s lanes: 1 port: e000
    bus-ID: 05:00.0 chip-ID: 10ec:8168 class-ID: 0200
  Device-2: Intel Wi-Fi 6E AX210/AX1675 2x2 [Typhoon Peak] driver: iwlwifi
    v: kernel pcie: gen: 2 speed: 5 GT/s lanes: 1 bus-ID: 06:00.0
    chip-ID: 8086:2725 class-ID: 0280
  IF: wlp6s0 state: up mac: <filter>
  IP v4: <filter> type: dynamic noprefixroute scope: global
    broadcast: <filter>
  IP v6: <filter> scope: link
  IP v6: <filter> type: noprefixroute scope: link
  Info: services: NetworkManager, smbd, sshd, systemd-networkd,
    systemd-timesyncd, wpa_supplicant
  WAN IP: <filter>

There are apparently two drivers for this - to use one, blacklist the other.

How can I switch from r8169 to r8168 on an installed system? - Kernel, boot, graphics & hardware - EndeavourOS

One is in the kernel already (I think) - the other needs to be installed separately.
Now you have two for the same hardware - one of them should work.
The other needs to be blacklisted.

sudo modprobe r8169

doesn’t load it?

Is it blacklisted?

Use a different kernel?

1 Like

Hi @michaldybczak ,
Maybe you could ask this question in the Tuxedo support or forum.

Anyway, I wonder whether you can read the following links in order to solve the problem:
[SOLVED] Problems with RTL8111/8168/8411 PCI Express Gigabit Ethernet / Kernel & Hardware / Arch Linux Forums

Network configuration/Ethernet - ArchWiki

Otherwise, you could try this:
AUR (en) - r8168-dkms

Hope it help,
Regards