Wired network issues after recent updates: error on boot, and random disconnects

Intrinsic · Post by **Intrinsic** » Wed May 16, 2018 9:31 pm

Relevant system info:

System:    Host: mintbox Kernel: 4.13.0-41-generic x86_64 (64 bit gcc: 5.4.0)
           Desktop: Cinnamon 3.6.7 (Gtk 3.18.9-1ubuntu3.3)
           Distro: Linux Mint 18.3 Sylvia

Network:   Card: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
           driver: r8169 v: 2.3LK-NAPI port: d000 bus-ID: 03:00.0
           IF: enp3s0 state: up speed: 100 Mbps duplex: full
           mac: 4c:cc:6a:60:23:5e

Issue defined:

On boot I now see the following error:

Code: Select all

Failed to start Raise network interfaces
see 'systemctl status networking.service' for details

About the time this issue appeared the network drive mappings in /etc/fstab stopped mapping on boot (someone helped me with a work around for this already )

Once the machine starts the network works, but a desktop tool tip will randomly notify me that my wired connection has been disconnected, and then a few seconds later it'll state the connection has been established again. The interval of time before this brief disconnect happens is pretty random, anywhere from almost right away to many minutes after boot.

The network starts out with a 1000 Mbps link speed, and will drop down to a 100 Mbps link speed after the connection drops and comes back.

More info and speculation:

I did check to make sure the network cable wasn't damaged or pulling out of the PC or switch. Nothing has physically changed and the managed switch the computer is plugged into is not rebooting or anything like that. I suspect this is a software issue caused by recent updates...I have been installing ALL the updates, but haven't been paying close attention, so I'm not exactly sure when the issue started (a few weeks ago maybe?)

I have been using the 4.13 kernel series for some time now, and for a long time I've not had any of these problems.

Tried kernels 4.15.0-20, 4.4.0-124, and 4.10.0-42 for the heck of it, and they didn't help, so I went back to the 4.13 series

The output I get when running 'systemctl status networking.service' is :

Code: Select all

● networking.service - Raise network interfaces
   Loaded: loaded (/lib/systemd/system/networking.service; enabled; vendor prese
  Drop-In: /run/systemd/generator/networking.service.d
           └─50-insserv.conf-$network.conf
   Active: failed (Result: exit-code) since Wed 2018-05-16 17:46:57 PDT; 7min ag
     Docs: man:interfaces(5)
  Process: 851 ExecStart=/sbin/ifup -a --read-environment (code=exited, status=1
  Process: 843 ExecStartPre=/bin/sh -c [ "$CONFIGURE_INTERFACES" != "no" ] && [ 
 Main PID: 851 (code=exited, status=1/FAILURE)

May 16 17:46:57 mintbox sudo[937]: pam_unix(sudo:session): session opened for us
May 16 17:46:57 mintbox ifup[851]: mount error(101): Network is unreachable
May 16 17:46:57 mintbox ifup[851]: Refer to the mount.cifs(8) manual page (e.g. 
May 16 17:46:57 mintbox sudo[937]: pam_unix(sudo:session): session closed for us
May 16 17:46:57 mintbox ifup[851]: run-parts: /etc/network/if-up.d/samba-mount e
May 16 17:46:57 mintbox ifup[851]: /sbin/ifup: post-up script failed.
May 16 17:46:57 mintbox systemd[1]: networking.service: Main process exited, cod
May 16 17:46:57 mintbox systemd[1]: Failed to start Raise network interfaces.
May 16 17:46:57 mintbox systemd[1]: networking.service: Unit entered failed stat
May 16 17:46:57 mintbox systemd[1]: networking.service: Failed with result 'exit

If you'd like more info please ask, and any suggestions would be greatly appreciated.

EDIT:
A new network cable mostly solved the issue. Even though the old one didn't look physically damaged after it was replace I no longer get the intermittent disconnects and the connection dropping back to 100Mbps. Because effectively everything works the error on boot is much less important, but if someone knows what to do about that error please let me know.