ethernet wont work with Realtek r8125 [SOLVED]

IonizedBanana · 2025-03-11 04:35:49

just did a real arch install for the first time on my main desktop after using it for over a year on my laptop, but I cannot for the life of me get ethernet to work. Im using iwd for wifi (which works fine) and ive enabled network configuration for iwd. Ive made sure both systemd-networkd and systemd-resolved are enabled and started, Ive set the device to up with ip link, and I tried a kernel module from the aur (r8125-dkms) but it didnt seem to do anything. as far as I can tell, the r8169 driver included in the kernel is supposed to support the ethernet card, but I cant seem to get it to work.

output of lspci -v -d ::0200

72:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller (rev 05)
	Subsystem: ASRock Incorporation Device 8125
	Flags: bus master, fast devsel, latency 0, IRQ 42, IOMMU group 24
	I/O ports at f000 [size=256]
	Memory at dc700000 (64-bit, non-prefetchable) [size=64K]
	Memory at dc710000 (64-bit, non-prefetchable) [size=16K]
	Capabilities: <access denied>
	Kernel driver in use: r8169
	Kernel modules: r8169

output of 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 noprefixroute 
       valid_lft forever preferred_lft forever
2: enp114s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 9c:6b:00:80:12:4b brd ff:ff:ff:ff:ff:ff
    altname enx9c6b0080124b
    inet6 2600:1700:3800:b1e0:9e6b:ff:fe80:124b/64 scope global dynamic mngtmpaddr proto kernel_ra 
       valid_lft 3270sec preferred_lft 3270sec
    inet6 fe80::9e6b:ff:fe80:124b/64 scope link proto kernel_ll 
       valid_lft forever preferred_lft forever
4: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 78:46:5c:91:f2:cd brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.153/24 scope global dynamic noprefixroute wlan0
       valid_lft 85738sec preferred_lft 85738sec
    inet6 2600:1700:3800:b1e0::27/128 scope global dynamic noprefixroute 
       valid_lft 2941sec preferred_lft 2941sec
    inet6 fe80::7a46:5cff:fe91:f2cd/64 scope link proto kernel_ll 
       valid_lft forever preferred_lft forever

I suspect this is some driver conflict or a missing dependency, I just dont know where else to look.

Last edited by IonizedBanana (2025-03-13 05:31:08)

xerxes_ · 2025-03-11 10:31:02

There is a package r8168-lts with extra kernel module for linux-lts. Maybe it will work.

seth · 2025-03-11 14:55:11

dkms will require the linux-*headers package for the concerned kernels to actually build the module.
Check "dkms status"

I don't think the 8168 module will be able to drive a 8125 chip

IonizedBanana · 2025-03-11 18:40:44

seth wrote:

dkms will require the linux-*headers package for the concerned kernels to actually build the module.

did not know that, thanks, but I just installed headers and the module initialized, still nothing.

new output of lspci -v -d ::0200:

72:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller (rev 05)
	Subsystem: ASRock Incorporation Device 8125
	Flags: bus master, fast devsel, latency 0, IRQ 42, IOMMU group 24
	I/O ports at f000 [size=256]
	Memory at dc700000 (64-bit, non-prefetchable) [size=64K]
	Memory at dc710000 (64-bit, non-prefetchable) [size=16K]
	Capabilities: <access denied>
	Kernel driver in use: r8125
	Kernel modules: r8169, r8125

i blacklisted the old module to make sure it was using r8125, looks to me like that worked

IonizedBanana · 2025-03-12 03:17:29

after a little more digging ive found this in my journal:

Mar 11 18:36:57 arch kernel: r8125: loading out-of-tree module taints kernel.
Mar 11 18:36:57 arch kernel: r8125: module verification failed: signature and/or required key missing - tainting kernel
Mar 11 18:36:57 arch kernel: r8125 Ethernet controller driver 9.015.00-NAPI loaded
Mar 11 18:36:57 arch kernel: r8125: This product is covered by one or more of the following patents: US6,570,884, US6,115,776, and US6,327,625.
Mar 11 18:36:57 arch kernel: r8125  Copyright (C) 2024 Realtek NIC software team <nicfae@realtek.com> 
Mar 11 18:36:58 arch kernel: r8125 0000:72:00.0 enp114s0: renamed from eth0

tried uninstalling and reinstalling, not sure what else to do?

seth · 2025-03-12 07:29:46

The module ended up being used and those journal messages are uncritical (every OOT module "taints" the kernel)
Maybe we should start to look at "how" your ethernet "won't work"
Please post the output of

ip a
ip r
find /etc/systemd -type l -exec test -f {} \; -print | awk -F'/' '{ printf ("%-40s | %s\n", $(NF-0), $(NF-1)) }' | sort -f

IonizedBanana · 2025-03-12 19:48:39

ip a while wifi disconnected:

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 noprefixroute 
       valid_lft forever preferred_lft forever
2: enp114s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 9c:6b:00:80:12:4b brd ff:ff:ff:ff:ff:ff
    altname enx9c6b0080124b
    inet6 2600:1700[glep] scope global dynamic mngtmpaddr proto kernel_ra 
       valid_lft 3367sec preferred_lft 3367sec
    inet6 fe80::9e6b:ff:fe80:124b/64 scope link proto kernel_ll 
       valid_lft forever preferred_lft forever
4: wlan0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 78:46:5c:91:f2:cd brd ff:ff:ff:ff:ff:ff
    inet6 fe80::7a46:5cff:fe91:f2cd/64 scope link proto kernel_ll 
       valid_lft forever preferred_lft forever

ip r wont return anything on ethernet

it works on the arch iso, so maybe im missing something, but I dont see anything on the wiki besides drivers, which I installed with the r8125-dkms, and its still using that module to drive the card. I imagine dns and everything is setup fine if it works great on wifi.
long one:

dbus-org.freedesktop.network1.service    | system
dbus-org.freedesktop.resolve1.service    | system
dbus-org.freedesktop.timesync1.service   | system
display-manager.service                  | system
getty@tty1.service                       | getty.target.wants
gnome-keyring-daemon.socket              | sockets.target.wants
iwd.service                              | multi-user.target.wants
nmb.service                              | multi-user.target.wants
p11-kit-server.socket                    | sockets.target.wants
pipewire.socket                          | sockets.target.wants
pulseaudio.socket                        | sockets.target.wants
remote-fs.target                         | multi-user.target.wants
systemd-networkd.service                 | multi-user.target.wants
systemd-networkd.socket                  | sockets.target.wants
systemd-networkd-wait-online.service     | network-online.target.wants
systemd-network-generator.service        | sysinit.target.wants
systemd-resolved.service                 | sysinit.target.wants
systemd-timesyncd.service                | sysinit.target.wants
systemd-userdbd.socket                   | sockets.target.wants
xdg-user-dirs-update.service             | default.target.wants

ip a on wifi:

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 noprefixroute 
       valid_lft forever preferred_lft forever
2: enp114s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 9c:6b:00:80:12:4b brd ff:ff:ff:ff:ff:ff
    altname enx9c6b0080124b
    inet6 2600:1700:[glep]64 scope global dynamic mngtmpaddr proto kernel_ra 
       valid_lft 3225sec preferred_lft 3225sec
    inet6 fe80::9e6b:ff:fe80:124b/64 scope link proto kernel_ll 
       valid_lft forever preferred_lft forever
4: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 78:46:5c:91:f2:cd brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.153/24 scope global dynamic noprefixroute wlan0
       valid_lft 86267sec preferred_lft 86267sec
    inet6 2600:1700:3800:b1e0::27/128 scope global dynamic noprefixroute 
       valid_lft 3470sec preferred_lft 3470sec
    inet6 fe80::7a46:5cff:fe91:f2cd/64 scope link proto kernel_ll 
       valid_lft forever preferred_lft forever

ip r on wifi

default via 192.168.1.254 dev wlan0 proto dhcp src 192.168.1.153 metric 304 
192.168.1.0/24 dev wlan0 proto dhcp scope link metric 304

Last edited by IonizedBanana (2025-03-12 21:53:51)

seth · 2025-03-12 21:04:48

Obfuscate the number that starts w/ "2600:1700", it's a publically routable IPv6 in south carolina.
You don't get an IPv4 lease for the ethernet - I guess iwd dwill get you one for the wifi, but you simply haven't configured the NIC for systemd-networkd?
https://wiki.archlinux.org/title/System … using_DHCP

IonizedBanana · 2025-03-12 22:10:26

seth wrote:

you simply haven't configured the NIC for systemd-networkd?

will try this when I get off of work tonight, but genuinely how did you come to this conclusion? is there some glaring thing I'm missing? educated guess?

seth · 2025-03-12 22:19:09

You don't have a wired lease, so either nothing tries to obtain a lease or the request fails.
You've a wireless lease.
iwd can optionally do dhcp by itself, but only will for wireless NICs (obviously)
Having to configure individial NICs for networkd frequently comes as surprise for its users.
There's no other network service (eg. dhcpcd) that would get a lease on the wired connection.

So either you didn't configure the nic or misconfigured it or the dhcp server snubs you.
This is in order of probability, so we want to look at the obvious problem first.

And your reply wasn't "No, I certainly configured that NIC!" …

IonizedBanana · 2025-03-12 22:32:46

seth wrote:

Having to configure individial NICs for networkd frequently comes as surprise for its users.

yeah, I didnt know that either, I would've thought the install wiki page wouldve had something at least mentioning configuring that stuff but as far as I can tell it isnt there

edit: I found it under the ethernet section of network configuration, I realize now my mistake was assuming iwd would do *all* my dhcp, not just wireless

And your reply wasn't "No, I certainly configured that NIC!" …

I certainly didn't lol, hopefully that solves it, we shall see tonight

Last edited by IonizedBanana (2025-03-12 22:45:19)

seth · 2025-03-12 22:49:09

https://wiki.archlinux.org/title/Instal … figuration
=> https://wiki.archlinux.org/title/Networ … k_managers
==> https://wiki.archlinux.org/title/System … n_examples

iwd does not default to configuring the network either, but if one has/cares about only wifi, it's not a bad option and one might then go on to project that setup as only option to ones audience in a youtube video, silently implying that that audience also only cares about wifi.

IonizedBanana · 2025-03-12 23:14:23

seth wrote:

project that setup as only option to ones audience in a youtube video, silently implying that that audience also only cares about wifi.

I see what you did there, but iwd was all me, the video used networkmanager

I prefer iwd over networkmanager on my laptop since it always seems to be faster at reconnecting for me, and I wanted my two installs to be as similar as possible. forgot that prior to iwd I used networkmanager which is (maybe) why my laptop would work with ethernet out the box

IonizedBanana · 2025-03-13 05:18:40

we shall see tonight

it worked

xerxes_ · 2025-03-14 09:53:55

@seth
Would NetworkManager setup dhcp for both ethernet and wifi (and maybe for mobile too)?

Last edited by xerxes_ (2025-03-14 09:54:31)

seth · 2025-03-14 10:16:11

Yes, of course - every manager (including just dhcpcd and in this case networkd) can configure all NICs that have a carrier - but the OP deliberately dropped NM.
I think NM defaults to falling over behavior, though (use ethernet and if there's no ethernet, use the wifi), while other services will require more configuration (using ifplugd or so)

iwd is limited to configuring the wifi NICs because it primarily provides a wifi carrier (like wpa_supplicant)

Arch Linux

#1 2025-03-11 04:35:49

ethernet wont work with Realtek r8125 [SOLVED]

#2 2025-03-11 10:31:02

Re: ethernet wont work with Realtek r8125 [SOLVED]

#3 2025-03-11 14:55:11

Re: ethernet wont work with Realtek r8125 [SOLVED]

#4 2025-03-11 18:40:44

Re: ethernet wont work with Realtek r8125 [SOLVED]

#5 2025-03-12 03:17:29

Re: ethernet wont work with Realtek r8125 [SOLVED]

#6 2025-03-12 07:29:46

Re: ethernet wont work with Realtek r8125 [SOLVED]

#7 2025-03-12 19:48:39

Re: ethernet wont work with Realtek r8125 [SOLVED]

#8 2025-03-12 21:04:48

Re: ethernet wont work with Realtek r8125 [SOLVED]

#9 2025-03-12 22:10:26

Re: ethernet wont work with Realtek r8125 [SOLVED]

#10 2025-03-12 22:19:09

Re: ethernet wont work with Realtek r8125 [SOLVED]

#11 2025-03-12 22:32:46

Re: ethernet wont work with Realtek r8125 [SOLVED]

#12 2025-03-12 22:49:09

Re: ethernet wont work with Realtek r8125 [SOLVED]

#13 2025-03-12 23:14:23

Re: ethernet wont work with Realtek r8125 [SOLVED]

#14 2025-03-13 05:18:40

Re: ethernet wont work with Realtek r8125 [SOLVED]

#15 2025-03-14 09:53:55

Re: ethernet wont work with Realtek r8125 [SOLVED]

#16 2025-03-14 10:16:11

Re: ethernet wont work with Realtek r8125 [SOLVED]

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