I am facing the same problem presented here but none of the given solutions seem to work. I am using ubuntu 18.04 and I cannot connect using my ethernet cable -the network manager shows "Unmanaged" under the wired connection. The wireless adapter works fine. I tried the work around of turning "managed" to "true" in /etc/networkmanager/networkmanager.conf but nothing changed even after fully rebooting the computer.
I have changed the content of /etc/netplan/01-network-manager-all.yaml From:
# Let NetworkManager manage all devices on this system
network:
version: 2
renderer: NetworkManager
To:
# Let NetworkManager manage all devices on this system
network:
version: 2
renderer: NetworkManager
ethernets:
enp8s0:
dhcp4: yes
Adding "ethernets: enp8s0: dhcp4: yes"
The output of sudo lshw -C network is:
*-network
description: Wireless interface
product: Wireless 7260
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:07:00.0
logical name: wlp7s0
version: 73
serial: a0:a8:cd:13:30:cb
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=iwlwifi driverversion=4.15.0-96-generic firmware=17.948900127.0 ip=192.168.1.6 latency=0 link=yes multicast=yes wireless=IEEE 802.11
resources: irq:31 memory:d1500000-d1501fff
*-network DISABLED
description: Ethernet interface
product: QCA8171 Gigabit Ethernet
vendor: Qualcomm Atheros
physical id: 0
bus info: pci@0000:08:00.0
logical name: enp8s0
version: 10
serial: 60:02:92:25:97:36
capacity: 1Gbit/s
width: 64 bits
clock: 33MHz
capabilities: pm pciexpress msi msix bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=alx latency=0 link=no multicast=yes port=twisted pair
resources: irq:18 memory:d1400000-d143ffff ioport:3000(size=128)
The output of lspci -nnk shows that the kernel driver in use is "alx".
Trying "sudo ifconfig enp8s0 up" does result in enp8s0 appearing in the output of my ifconfig but the "unmanaged" is still there and I cannot connect to the internet using the wired connection.. I have also tried "sudo ip link set enp8s0 up". It just removes the "disabled" from the lshw -C network... but still nothing seems to work.
Any suggestions would be really welcome. Thank you!