I've just started seeing something odd in my system (Ubuntu 20.04.03 LTS). I've got a hardwired connection to my system, and noticed in the past few days that I see the interface enp0s25 as one of my pulldown options for a wired connection. I saw that /etc/NetworkManager/system-connections has a list of all my wireless and wired connections, and saw a file 'enp0s25.nmconnection' there. I moved it someplace else, and rebooted.
However, this connection still appears in my pulldown, and for some reason, even if I set my wired connection to 'Off'... this still reappears. If I set things to 'Off', my system is connected to enp0s25.nmconnection, but there is no internet connectivity. Here is how things appear when the system is connected normally; note the enp0s25 is there:
Looking at /etc/NetworkManager/system-connections, I don't see the enp0s25.nmconnection there. How might this be repopulated? Is there a way to find what process might be trying to reconnect this?
I do use Dropbox, so I'm wondering if this could be an issue. The hardware (MAC) addresses of the 'Wired connection 1' and enp0s25 are the same, BTW.
Additionally, even when I remove the interface enp0s25, it can reappear, and, looking further, I see it has the 'Make available to other users' checkbox 'on'.
The output of 'ifconfig' shows the enp0s25 interface, when 'Wired connection 1' is connected.
As per @heynnma:
No entries for /etc/network/interfaces;
ls /etc/network returns:
if-down.d if-post-down.d if-pre-up.d if-up.d
In /etc/netplan, there is only one file, 01-network-manager-all.yaml
# Let NetworkManager manage all devices on this system
network:
version: 2
renderer: NetworkManager
Trying sudo lshw -C network, gives the following (MAC address output obscured):
*-network
description: Ethernet interface
product: Ethernet Connection I217-LM
vendor: Intel Corporation
physical id: 19
bus info: pci@0000:00:19.0
logical name: enp0s25
version: 04
serial: aa:bb:cc:dd:ee:ff
size: 100Mbit/s
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=5.11.0-41-generic duplex=full firmware=0.13-3 ip=10.0.0.52 latency=0 link=yes multicast=yes port=twisted pair speed=100Mbit/s
resources: irq:37 memory:f2600000-f261ffff memory:f263f000-f263ffff ioport:5080(size=32)
*-network DISABLED
description: Wireless interface
product: Wireless 7260
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:04:00.0
logical name: wlp4s0
version: 83
serial: a0:b0:c0:d0:e0:f0
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=iwlwifi driverversion=5.11.0-41-generic firmware=17.3216344376.0 7260-17.ucode latency=0 link=no multicast=yes wireless=IEEE 802.11
resources: irq:36 memory:f2400000-f2401fff
Here's the thing - I didn't have a wireless connection on my machine (always have been hardwired; this is a Desktop installation). I did have a wireless adapter, and added the system to a local Wi-Fi connection to see if this would change things. This did stop the appearance of the enp0s25, temporarily, however, the 'Turn Off' dropdown went away! The only way to disconnect is to open the 'Wired settings' option, and disconnect via the slider. However, when that happens... the enp0s25 reappears again as in the screen shot.
