On a Lenovo P50, the network card does not seem to be able to detect Ethernet cables or establish a network connection. The ethernet conection is set-up to be hot-plugged and managed by
avahi. The wired connection once worked, but seems to have failed some time in the past six months or so.
$ cat /etc/lsb-release DISTRIB_ID=Ubuntu DISTRIB_RELEASE=16.04 DISTRIB_CODENAME=xenial DISTRIB_DESCRIPTION="Ubuntu 16.04.3 LTS"
$ cat /proc/version Linux version 4.4.0-112-generic ([email protected]) (gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.5) ) #135-Ubuntu SMP Fri Jan 19 11:48:36 UTC 2018
$ lspci | grep Ethernet 00:1f.6 Ethernet controller: Intel Corporation Ethernet Connection (2) I219-LM (rev 31)
$ sudo lshw -C network *-network description: Wireless interface product: Wireless 8260 vendor: Intel Corporation physical id: 0 bus info: [email protected]:04:00.0 logical name: wlp4s0 version: 3a serial: 44:85:00:a1:31:5a width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless configuration: broadcast=yes driver=iwlwifi driverversion=4.4.0-112-generic firmware=16.242414.0 ip=172.20.174.88 latency=0 link=yes multicast=yes wireless=IEEE 802.11abgn resources: irq:133 memory:c4c00000-c4c01fff *-network description: Ethernet interface product: Ethernet Connection (2) I219-LM vendor: Intel Corporation physical id: 1f.6 bus info: [email protected]:00:1f.6 logical name: enp0s31f6 version: 31 serial: 50:7b:9d:e4:d8:49 capacity: 1Gbit/s width: 32 bits clock: 33MHz capabilities: pm msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=3.2.6-k firmware=0.8-3 latency=0 link=no multicast=yes port=twisted pair resources: irq:130 memory:c5700000-c571ffff
$ ifconfig enp0s31f6 Link encap:Ethernet HWaddr 50:7b:9d:e4:d8:49 UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) Interrupt:16 Memory:c5700000-c5720000 enp0s31f6:avahi Link encap:Ethernet HWaddr 50:7b:9d:e4:d8:49 inet addr:169.254.10.47 Bcast:169.254.255.255 Mask:255.255.0.0 UP BROADCAST MULTICAST MTU:1500 Metric:1 Interrupt:16 Memory:c5700000-c5720000 ...
$ ifplugstatus lo: link beat detected enp0s31f6: unplugged
$ cat /etc/network/interfaces # interfaces(5) file used by ifup(8) and ifdown(8) auto lo iface lo inet loopback allow-hotplug enp0s31f6 iface enp0s31f6 inet dhcp
This question seems specific to a USB Ethernet device, related to hot-plug issues.
This question involves the network interface disappearing entirely, and returning on reboot.
This question is a bit vague and lacks definitive answers.
This question pertains to Ethernet, but the answer is a link to wifi troubleshooting.
This question appears to be different, as it involves the Ethernet adapter being unavailable, wheres it is available on my machine but registers as disconnected.
This question has similar symptoms, but was due to a conflicting configuration from a previous network card.
This question related to a corrupted driver (I think?).
This question was diagnosed as a hardware fault of the network card. It is not clear that it applies in this case. This one seemed also to be a hardware failure. (I would like to rule out other explanations before presuming hardware failure).