Ethernet connection fails after reboot

Since today I have strange issues with my ethernet connection on Manjaro.
To make sure the issue was not on my connection side, I can confirm the network connects instantly and works well under Windows, but when I reboot on Manjaro it just fails and fails and so on… after rebooting a lot and restarting the router and deleting/recreating the connection in Network, in short insisting A LOT, then at some point it connects after a reboot or after failing a lot.

Here is my inxi:

[omano@omano-nvme ~]$ inxi -Fazy
System:
  Kernel: 5.8.11-1-MANJARO x86_64 bits: 64 compiler: N/A 
  parameters: BOOT_IMAGE=/boot/vmlinuz-5.8-x86_64 
  root=UUID=6a81f472-9ea9-40f8-85f6-7925c4bbe742 rw quiet splash apparmor=1 
  security=apparmor udev.log_priority=3 
  Desktop: KDE Plasma 5.19.5 tk: Qt 5.15.1 wm: kwin_x11 dm: SDDM 
  Distro: Manjaro Linux 
Machine:
  Type: Desktop System: Gigabyte product: B450M DS3H v: N/A serial: <filter> 
  Mobo: Gigabyte model: B450M DS3H-CF v: x.x serial: <filter> 
  UEFI: American Megatrends v: F51f date: 07/02/2020 
CPU:
  Topology: 6-Core model: AMD Ryzen 5 3600 bits: 64 type: MT MCP arch: Zen 2 
  family: 17 (23) model-id: 71 (113) stepping: N/A microcode: 8701021 
  L2 cache: 3072 KiB 
  flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm 
  bogomips: 86269 
  Speed: 2053 MHz min/max: 2200/3600 MHz boost: enabled Core speeds (MHz): 
  1: 2053 2: 2053 3: 2191 4: 2194 5: 3593 6: 2197 7: 2196 8: 2195 9: 2049 
  10: 2053 11: 3594 12: 2196 
  Vulnerabilities: Type: itlb_multihit status: Not affected 
  Type: l1tf status: Not affected 
  Type: mds status: Not affected 
  Type: meltdown status: Not affected 
  Type: spec_store_bypass 
  mitigation: Speculative Store Bypass disabled via prctl and seccomp 
  Type: spectre_v1 
  mitigation: usercopy/swapgs barriers and __user pointer sanitization 
  Type: spectre_v2 mitigation: Full AMD retpoline, IBPB: conditional, STIBP: 
  conditional, RSB filling 
  Type: srbds status: Not affected 
  Type: tsx_async_abort status: Not affected 
Graphics:
  Device-1: NVIDIA GP106 [GeForce GTX 1060 6GB] vendor: eVga.com. 
  driver: nvidia v: 450.66 alternate: nouveau,nvidia_drm bus ID: 07:00.0 
  chip ID: 10de:1c03 
  Display: x11 server: X.Org 1.20.9 compositor: kwin_x11 driver: nvidia 
  display ID: :0 screens: 1 
  Screen-1: 0 s-res: 1680x1050 s-dpi: 87 s-size: 490x321mm (19.3x12.6") 
  s-diag: 586mm (23.1") 
  Monitor-1: DVI-D-0 res: 1680x1050 dpi: 87 size: 490x320mm (19.3x12.6") 
  diag: 585mm (23") 
  OpenGL: renderer: GeForce GTX 1060 6GB/PCIe/SSE2 v: 4.6.0 NVIDIA 450.66 
  direct render: Yes 
Audio:
  Device-1: NVIDIA GP106 High Definition Audio vendor: eVga.com. 
  driver: snd_hda_intel v: kernel bus ID: 07:00.1 chip ID: 10de:10f1 
  Device-2: AMD Starship/Matisse HD Audio vendor: Gigabyte 
  driver: snd_hda_intel v: kernel bus ID: 09:00.4 chip ID: 1022:1487 
  Sound Server: ALSA v: k5.8.11-1-MANJARO 
Network:
  Device-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet 
  vendor: Gigabyte driver: r8169 v: kernel port: f000 bus ID: 05:00.0 
  chip ID: 10ec:8168 
  IF: enp5s0 state: up speed: 100 Mbps duplex: full mac: <filter> 
Drives:
  Local Storage: total: 2.03 TiB used: 436.87 GiB (21.0%) 
  SMART Message: Unable to run smartctl. Root privileges required. 
  ID-1: /dev/nvme0n1 vendor: Crucial model: CT1000P1SSD8 size: 931.51 GiB 
  block size: physical: 512 B logical: 512 B speed: 31.6 Gb/s lanes: 4 
  serial: <filter> rev: P3CR020 scheme: GPT 
  ID-2: /dev/sda vendor: SanDisk model: SSD PLUS 480GB size: 447.14 GiB 
  block size: physical: 512 B logical: 512 B speed: 6.0 Gb/s serial: <filter> 
  rev: 00RL scheme: MBR 
  ID-3: /dev/sdb vendor: Western Digital model: WD5001AALS-00E3A0 
  size: 465.76 GiB block size: physical: 512 B logical: 512 B speed: 3.0 Gb/s 
  serial: <filter> rev: 1D05 scheme: MBR 
  ID-4: /dev/sdc vendor: SanDisk model: SDSSDHP256G size: 238.47 GiB 
  block size: physical: 512 B logical: 512 B speed: 6.0 Gb/s serial: <filter> 
  rev: 6RL scheme: GPT 
Partition:
  ID-1: / raw size: 931.22 GiB size: 915.60 GiB (98.32%) 
  used: 436.86 GiB (47.7%) fs: ext4 dev: /dev/nvme0n1p2 
Swap:
  Alert: No Swap data was found. 
Sensors:
  System Temperatures: cpu: 54.2 C mobo: N/A gpu: nvidia temp: 49 C 
  Fan Speeds (RPM): N/A gpu: nvidia fan: 8% 
Info:
  Processes: 277 Uptime: 5m Memory: 15.65 GiB used: 1.88 GiB (12.0%) 
  Init: systemd v: 246 Compilers: gcc: 10.2.0 clang: 10.0.1 Packages: 
  pacman: 1403 lib: 382 flatpak: 0 Shell: Bash v: 5.0.18 running in: konsole 
  inxi: 3.1.05 

So the issue is that the NetworkManager fails to connect to my router, with error popup saying (translated) Ethernet connection disabled followed instantly by the IP configuration was unavailable

I tried to disable NetworkManager and switch for DHCPCD but when it fails with NetworkManager, it also doesn’t work with DHCPCD. So I’m back with NetworkManager for now.

So right now I am connected it works good, like before, but for the next time, how would be the proper way to troubleshoot, what info would be relevant to look at, what logs and which specific keywords in these logs would be the best to try to find the issue?

If anyone can give some advices, I’m all ears because I’m lost currently and when it happens I’m just not fixing anything, I think it just works again by itself for unknown reason.

I kinda found a temporary way to fix my issue, but I found a post really similar to my issue here [Stable Update] 2020-08-28 - Kernels, Systemd, PAM, PAMBASE, KDE-git, Deepin, Pamac, Nvidia 450.66, LibreOffice 7.0 - #73 by Hanzel
His issue mysteriously was there for a moment then it worked at some point after the non sense he tried like me.

I found what changed in the past week on my Manjaro, for a thread I replied to, I changed my DNS server in Network Manager, I had set cloud flare DNS servers, everything was working as expected for days.
The issue was not about the DNS server at all, BUT by manually setting the DNS server as 192.168.1.1 (the router IP address which was automatically set in theory with full AUTO in N.M.) then it connects properly, but here is the issue in log, like the guy above:

[omano@omano-nvme ~]$ journalctl -k -p err -b -1
-- Logs begin at Sun 2020-09-13 02:58:12 CEST, end at Fri 2020-09-25 21:35:51 CEST. --
sept. 25 16:32:56 omano-nvme kernel: sp5100-tco sp5100-tco: Watchdog hardware is disabled
sept. 25 16:33:25 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:35:12 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:35:22 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:36:28 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:36:53 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:37:28 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:37:53 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:38:28 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:38:53 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:39:22 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:39:32 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:40:57 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:41:32 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:42:59 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:43:30 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:43:55 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:44:25 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:45:30 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:45:35 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:45:55 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:46:30 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:46:55 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:47:36 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:47:46 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:47:56 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:48:25 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:48:55 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:49:29 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:49:55 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
sept. 25 16:50:30 omano-nvme kernel: r8169 0000:05:00.0 enp5s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).

Here is journalctl:

journalctl -u NetworkManager.service -f
-- Logs begin at Sun 2020-09-13 02:58:12 CEST. --
sept. 25 16:46:07 omano-nvme NetworkManager[552]: <warn>  [1601045167.1097] dhcp4 (enp5s0): request timed out
sept. 25 16:46:07 omano-nvme NetworkManager[552]: <warn>  [1601045167.1111] device (enp5s0): Activation: failed for connection 'Connexion Ethernet'
sept. 25 16:46:52 omano-nvme NetworkManager[552]: <warn>  [1601045212.0987] dhcp4 (enp5s0): request timed out
sept. 25 16:46:52 omano-nvme NetworkManager[552]: <warn>  [1601045212.0999] device (enp5s0): Activation: failed for connection 'Connexion Ethernet'
sept. 25 16:48:09 omano-nvme NetworkManager[552]: <warn>  [1601045289.1080] dhcp4 (enp5s0): request timed out
sept. 25 16:48:09 omano-nvme NetworkManager[552]: <warn>  [1601045289.1092] device (enp5s0): Activation: failed for connection 'Connexion Ethernet'
sept. 25 16:48:57 omano-nvme NetworkManager[552]: <warn>  [1601045337.1083] dhcp4 (enp5s0): request timed out
sept. 25 16:48:57 omano-nvme NetworkManager[552]: <warn>  [1601045337.1094] device (enp5s0): Activation: failed for connection 'Connexion Ethernet'
sept. 25 16:49:42 omano-nvme NetworkManager[552]: <warn>  [1601045382.1064] dhcp4 (enp5s0): request timed out
sept. 25 16:49:42 omano-nvme NetworkManager[552]: <warn>  [1601045382.1079] device (enp5s0): Activation: failed for connection 'Connexion Ethernet'

For now I can have proper connection by forcing the DNS server. That doesn’t make sense to me but OK, problem kinda fixed I guess.

// EDIT: it actually was just pure ‘luck’ or ‘mystery’, in the end nothing was fixed.

new magical fix/band-aid/nothing: I enabled IPV6 in my router (but still disabled in NetworkManager) as a last resort for the sake of trying, and it seems to work… I did that because an old TimeShift backup also has the issue now so it seems to be external to Manjaro now… :man_facepalming: :sweat_smile:

Spoiler from future still not fixed it was just another fluke

I reinstalled the network drivers through System Settings it seems to work so far…

inxi before:

Network:
  Device-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet 
  vendor: Gigabyte driver: r8169 v: kernel port: f000 bus ID: 05:00.0 
  chip ID: 10ec:8168 
  IF: enp5s0 state: up speed: 100 Mbps duplex: full mac: <filter> 

inxi now:

Network:
  Device-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet 
  vendor: Gigabyte driver: r8168 v: 8.048.03-NAPI modules: r8169 port: f000 
  bus ID: 05:00.0 chip ID: 10ec:8168 
  IF: enp5s0 state: up speed: 1000 Mbps duplex: full mac: <filter>

This topic was automatically closed 3 days after the last reply. New replies are no longer allowed.