Every time I boot Kubuntu picks the wrong network controller by default

[theyoyomaster]

I am trying to learn how to configure my system to specify which network adapter to use by default. I have a somewhat specific scenario, I have a Prism USB router that I use for VR gaming (it's a specific product that creates a discrete link between my windows desktop and my Quest 3 so that I get better performance when not tethered). It isn't supported in Linux so when I boot my PC into Kubuntu it is non-functional. Well, every single time I boot it decides that is the primary hard wired network connection and I have to manually select the real ethernet adapter on my motherboard that is plugged into my actual network.

I tried googling for network priorities and found a way to set it, but it never seems to work for my specific scenario. No matter what I do, Kubuntu wants to use the USB adapter over my integrated ethernet on my motherboard. Anyone have any thoughts?

[oshunluvr]

Please post the contents of /etc/netplan/01-network-manager-all.yaml (or similarly named file).

You can turn off a device with a netplan entry like:

network:
version: 2
ethernets:
interface:
activation-mode: off

[oshunluvr]

And state what version of Kubuntu you are using...

[oshunluvr]

I guess I assumed you have disabled the device in System Settings > Wifi & Internet then unchecked "Connect automatically..."

[theyoyomaster]

Please post the contents of /etc/netplan/01-network-manager-all.yaml (or similarly named file).

You can turn off a device with a netplan entry like:

network:
version: 2
ethernets:
interface:
activation-mode: off

All that's in that file is:

network:
version: 2
renderer: NetworkManager


I am on 25.04.

The device isn't listed discretely in system settings. It treats both as "Wired" and I am yet to find a way to manage them separately.

[oshunluvr]

What's the output of ip link

[theyoyomaster]

What's the output of ip link

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: enp14s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen
1000
link/ether 10:ff:e0:87:ff:9a brd ff:ff:ff:ff:ff:ff
altname enx10ffe087ff9a
3: enxc8a3629c9a41: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group defa
ult qlen 1000
link/ether c8:a3:62:9c:9a:41 brd ff:ff:ff:ff:ff:ff
4: wlp13s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether e8:47:3a:e7:95:a0 brd ff:ff:ff:ff:ff:ff
altname wlxe8473ae795a0




enp14s0 is the correct one, enxc8a3629c9a41 is the VR USB hub.

[oshunluvr]

Try editing the yaml file an add this below "renderer: NetworkManager"

ethernets:
   enxc8a3629c9a41:
      activation-mode: off​

Restart networking or log out or reboot.

[theyoyomaster]

Still defaulted to the USB hub but now there is an additional copy of it available.

[oshunluvr]

Ok, weird. Seems netplan takes over after UDEV has defined the device. Probably going to require a custom UDEV entry for it.

[theyoyomaster]

So for someone fairly new to Linux, what exactly does that mean and how would I go about learning how to do that?