Hate that Updates then no connection

[Schwarzer Kater]

E.g. ip a to get the name of your Ethernet interface and sudo dmesg | grep enXXX (enXXX = name of the interface).

And to prove it you could test it with "real" data transfer (copy a movie or something to another device with 2.5 to see the diffence to 1 Gbit/s).

[Qqmike]

mike@mike-System-Product-Name:~$ 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
2: enp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether 04:42:1a:0c:7d:bd brd ff:ff:ff:ff:ff:ff
inet 192.168.0.17/24 brd 192.168.0.255 scope global dynamic noprefixroute enp3s0
valid_lft 49940sec preferred_lft 49940sec
inet6 fe80::e913:d7dd:1575:7402/64 scope link noprefixroute
valid_lft forever preferred_lft forever

mike@mike-System-Product-Name:~$ sudo dmesg | grep enp3s0
[sudo] password for mike:
[ 0.906508] r8169 0000:03:00.0 enp3s0: renamed from eth0
[ 4.324836] r8169 0000:03:00.0 enp3s0: Link is Down
[ 7.227684] r8169 0000:03:00.0 enp3s0: Link is Up - 1Gbps/Full - flow control off
[ 7.227693] IPv6: ADDRCONF(NETDEV_CHANGE): enp3s0: link becomes ready
[ 108.642685] r8169 0000:03:00.0 enp3s0: Link is Down
[ 119.517011] r8169 0000:03:00.0 enp3s0: Link is Up - 1Gbps/Full - flow control off

[Schwarzer Kater]

1 Gbps (probably or possibly because you are missing the kernel driver/module mentioned above).

So do the other devices in your network have 2.5 Gbit/s ports, for example your modem - and do you use at least Cat 5e cables (probably you are)?
2.5 might not be that relevant for your internet speed yet, depending on the provided up- and download rates (at least in Europe this makes no difference for allmost all of the private internet connections at present).

[Qqmike]

It is a cat 5e cable. But I've lost sight of what we are doing, what I am measuring and why. It's just a simple LAN, so copying a movie ... from where to where? Etc. I am feeling this is all not too important. What would the speed 2.5 G have to do with the "what": no connection upon updating from Discover? We have probably spent enough time on it.

Unless ... it's the business of dkms.

r8125 is the Linux 2.5G Ethernet device driver released by RealTek for their network controller.
This package provides the dkms source code for the r8125 kernel modules. Kernel source or headers are required to compile these modules.
Canonical does not provide updates for r8125-dkms. Some updates may be provided by the Ubuntu community.

But then, what about

Kernel driver in use: r8169]
Kernel modules: r8169​

Apparently, and I'm guessing, with standard Linux kernels for K/Ubuntu, when you re-boot after a kernel upgrade, the modules are rebuilt "to match."

[Schwarzer Kater]

Yes, you are right - I meant it could be worth it to "prove" real 2.5, if it had shown as such in dmesg and your modem also could handle 2.5…
But it shows 1 and so the next step would be to install the proper kernel driver/module.

PS: Have… to… sleep… now… - nearly 3:30 AM here.

[Qqmike]

But it looks like it is already installed:
Kernel driver in use: r8169
which appears to be an upgraded version of r8125 (I'm just guessing, because 8125 is the controller).

Muon offers r8125-dkms, but that wouldn't seem to make sense.
Muon also offers a plain "dkms." Just: dkms.

DKMS is a framework designed to allow individual kernel modules to be upgraded without changing the whole kernel. It is also very easy to rebuild modules as you upgrade kernels.
Canonical provides critical updates for dkms until Sat Oct 21 2023.

But, not sure what good that would be ... ? I wonder what harm could be done by installing just plain dklm (although it is only supported through Oct 2023.

[Snowhog]

Installing dkms won’t hurt anything.

[Qqmike]

@Snowhog: Thanks.

[Schwarzer Kater]

Then make sure that the headers for the kernels that you use are installed (e.g. the meta-packages linux-headers-generic and possibly linux-headers-generic-hwe-22.04).
After that install dkms, if you did not already do that (I would reboot after this, but I am not sure if this is even necessary).
The final step is to install r8125-dkms (which would be the right one for your Ethernet controller) and reboot & test.

From now on it should be automatically included in future kernel updates.
And if something does not work you can remove it again.

This works similar like kernel drivers/modules for e.g Nvidia or VirtualBox do.

[Qqmike]

OK, thanks, Schwarzer-Kater! 👍

[Qqmike]

OK, re your post # 24, Done! We'll see how things go on future updates, especially kernel updates. Thanks.

Marking it Solved for now.

[Schwarzer Kater]

It would be interesting what lspci -v and sudo dmesg | grep enp3s0 show now.

[Qqmike]

If I read it right, it looks like r8169 still runs the show, as I suspected. Somehow, it IS the updated module version, maybe, of 8125, somehow.

Edit, added: So, it looks like it is ok to have more than one module available: "Kernel modules: r8169, r8125." Apparently, the system chooses what works best? or the latest updated module?

~$ lspci -v
​03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller (rev 05)
Subsystem: ASUSTeK Computer Inc. RTL8125 2.5GbE Controller
Flags: bus master, fast devsel, latency 0, IRQ 19
I/O ports at 4000 [size=256]
Memory at a0c00000 (64-bit, non-prefetchable) [size=64K]
Memory at a0c10000 (64-bit, non-prefetchable) [size=16K]
Capabilities: <access denied>
Kernel driver in use: r8169
Kernel modules: r8169, r8125

~$ sudo dmesg | grep enp3s0
[sudo] password for mike:
[ 0.934481] r8169 0000:03:00.0 enp3s0: renamed from eth0
[ 4.700843] r8169 0000:03:00.0 enp3s0: Link is Down
[ 7.620696] r8169 0000:03:00.0 enp3s0: Link is Up - 1Gbps/Full - flow control off
[ 7.620705] IPv6: ADDRCONF(NETDEV_CHANGE): enp3s0: link becomes ready

[Qqmike]

Anything remarkable about that output?

[Schwarzer Kater]

Sorry for the late answer, I only have very little time during this weekend (and are you sure you want to mark this thread as "Solved" already?).

Why should r8169 be an updated version of r8125? AFAIK they contain different code for different hardware and the built-in (?) r8169 is used as a fallback option for 2.5, running with 1.0 only then…

As your output shows: now both modules/drivers are there, but r8169 is still used for your Ethernet, as before.
Did you try blacklisting the r8169 in /etc/modprobe.d with a simple file - e.g. called "blacklist-r8169.conf" - containing blacklist r8169, reboot and see if after that the r8125 is used for your Ethernet?

Another quick question is, if it would be necessary to update your initramfs after a change …?