I'm having an issue with my Ubuntu 20.04 install where I have no ethernet interface and I can't find a way to get it back. My situation is very similar to this question but I'm unable to get access to an external NIC and I'm doubtful that would even work for me. I have a USB wifi dongle but it isn't recognized by the system and I've been unable to build the drivers (when I try to compile them I get a compilation error). When I did this install I chose the minimal install option which may be why the USB adapter isn't recognized.
Any help getting at least the ethernet connection working again would be really appreciated. I've spent a bunch of time customizing this install and I'd rather not have to go through and re-do all that work if I can avoid it. At the end of the day I can always re-install but I'd like to avoid it.
Background
This started with an issue with my screen resolution being stuck at 800x600 due to some driver issues. I've fixed this issue before but had forgotten exactly how so I did some Googling and followed a few solutions none of which worked for me. I had other things to deal with so I gave up on the issue and left the PC for a few weeks. When I got back around to this issue I also noticed that I no longer had a network connection. After trying a few things (none of which I can remember now), replacing the network cable, getting a new motherboard, CPU, and RAM (I wanted an upgrade anyways and thought maybe the ancient board I was using was finally dying) I realized something else was wrong.
I can't install anything directly on the machine, I've been able to install a few packages by downloading them and their dependencies on another machine, putting them on a USB, and installing them off the USB. Below is the output from a bunch of commands that I've seen in other threads.
ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
sudo lshw -C network
*-network UNCLAIMED
description: Ethernet controller
product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:25:00.0
version: 15
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress msix bus_master cap_list
configuration: latency=0
resources: ioport:f000(size=256) memory:f7504000-f7504fff memory:f7500000-f7503fff
lspci
00:00.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Root Complex
00:00.2 IOMMU: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) I/O Memory Management Unit
00:01.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge
00:01.3 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) PCIe GPP Bridge
00:02.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge
00:03.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge
00:03.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) PCIe GPP Bridge
00:04.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge
00:07.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge
00:07.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Internal PCIe GPP Bridge 0 to Bus B
00:08.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge
00:08.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Internal PCIe GPP Bridge 0 to Bus B
00:14.0 SMBus: Advanced Micro Devices, Inc. [AMD] FCH SMBus Controller (rev 59)
00:14.3 ISA bridge: Advanced Micro Devices, Inc. [AMD] FCH LPC Bridge (rev 51)
00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Data Fabric: Device 18h; Function 0
00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Data Fabric: Device 18h; Function 1
00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Data Fabric: Device 18h; Function 2
00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Data Fabric: Device 18h; Function 3
00:18.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Data Fabric: Device 18h; Function 4
00:18.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Data Fabric: Device 18h; Function 5
00:18.6 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Data Fabric: Device 18h; Function 6
00:18.7 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Data Fabric: Device 18h; Function 7
03:00.0 USB controller: Advanced Micro Devices, Inc. [AMD] Device 43bc (rev 02)
03:00.1 SATA controller: Advanced Micro Devices, Inc. [AMD] Device 43b8 (rev 02)
03:00.2 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 43b3 (rev 02)
20:04.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] 300 Series Chipset PCIe Port (rev 02)
20:05.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] 300 Series Chipset PCIe Port (rev 02)
20:06.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] 300 Series Chipset PCIe Port (rev 02)
20:07.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] 300 Series Chipset PCIe Port (rev 02)
25:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 15)
29:00.0 VGA compatible controller: NVIDIA Corporation GP107 [GeForce GTX 1050 Ti] (rev a1)
29:00.1 Audio device: NVIDIA Corporation GP107GL High Definition Audio Controller (rev a1)
2a:00.0 Non-Essential Instrumentation [1300]: Advanced Micro Devices, Inc. [AMD] Zeppelin/Raven/Raven2 PCIe Dummy Function
2a:00.2 Encryption controller: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) Platform Security Processor
2a:00.3 USB controller: Advanced Micro Devices, Inc. [AMD] Zeppelin USB 3.0 Host controller
2b:00.0 Non-Essential Instrumentation [1300]: Advanced Micro Devices, Inc. [AMD] Zeppelin/Renoir PCIe Dummy Function
2b:00.2 SATA controller: Advanced Micro Devices, Inc. [AMD] FCH SATA Controller [AHCI mode] (rev 51)
2b:00.3 Audio device: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) HD Audio Controller
cat /etc/netplan/01-netcfg.yaml
#Let NetworkManager manage all devices on this system
network:
version: 2
renderer: NetworkManager
modinfo r8168/modinfo r8169
Both of these commands generate a module not found message
Edit
After writing my question I tried installing the dkms and r8168-dkms and that worked fine but I still didn't have a network connection. I'm fairly certain I tried sudo modprobe r8169 at this point but I may not have. I also tried install linux-generic-hwe-20.04 as mentioned in another question and that didn't finish due to some errors.
After seeing @Terrance's comment I decided to try sudo modprobe r8169 again and that worked. Either I didn't actually run the command previously or my attempt to install linux-generic-hwe-20.04 worked just enough to get the driver working (I'm not sure if that's even possible).
The end result is that my system is working enough I should be able to fix it but I don't know the exact fix which irks me more
