Ethernet disconnecting every few hours

Brownie · July 13, 2026, 7:50pm

I reinstalled Endeavour on my PC after 6 months of not using it at all, and suddenly my ethernet stops working occasionally (usually every few hours). I tried installing the r8125 driver manually, I blocked some other driver (sudo bash -c ‘echo “blacklist r8169” > /etc/modprobe.d/r8169.conf’). It can be fixed by doing “sudo rmmod r8125” and “sudo modprobe r8125”, but only temporarily, and then it happens again in some hours. I’ve been dealing with this for like 3-4 days right now, and I feel more and more defeated..

Any help appreciated!!

inxi -nN
Network:
  Device-1: Realtek RTL8111/8168/8211/8411 PCI Express Gigabit Ethernet
    driver: N/A
  Device-2: Realtek RTL8125 2.5GbE driver: r8125
  IF: enp42s0 state: up speed: 1000 Mbps duplex: full mac: 2c:f0:5d:76:c7:ce

sudo nmcli dev status
DEVICE          TYPE       STATE      CONNECTION
enp42s0         ethernet   connected  Wired connection 1
ipv6leakintrf0  dummy      connected  pvpn-killswitch-ipv6
proton0         wireguard  connected  ProtonVPN CZ#59
lo              loopback   connected  lo

find /etc/systemd/system
/etc/systemd/system
/etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service
/etc/systemd/system/display-manager.service
/etc/systemd/system/autovt@.service
/etc/systemd/system/graphical.target.wants
/etc/systemd/system/graphical.target.wants/power-profiles-daemon.service
/etc/systemd/system/network-online.target.wants
/etc/systemd/system/network-online.target.wants/NetworkManager-wait-online.service
/etc/systemd/system/timers.target.wants
/etc/systemd/system/timers.target.wants/fstrim.timer
/etc/systemd/system/sysinit.target.wants
/etc/systemd/system/sysinit.target.wants/systemd-timesyncd.service
/etc/systemd/system/getty.target.wants
/etc/systemd/system/getty.target.wants/getty@tty1.service
/etc/systemd/system/dbus-org.freedesktop.timesync1.service
/etc/systemd/system/default.target
/etc/systemd/system/multi-user.target.wants
/etc/systemd/system/multi-user.target.wants/avahi-daemon.service
/etc/systemd/system/multi-user.target.wants/lm_sensors.service
/etc/systemd/system/multi-user.target.wants/firewalld.service
/etc/systemd/system/multi-user.target.wants/NetworkManager.service
/etc/systemd/system/multi-user.target.wants/proton.VPN.service
/etc/systemd/system/multi-user.target.wants/remote-fs.target
/etc/systemd/system/dbus-org.freedesktop.nm-dispatcher.service
/etc/systemd/system/sockets.target.wants
/etc/systemd/system/sockets.target.wants/avahi-daemon.socket
/etc/systemd/system/sockets.target.wants/systemd-userdbd.socket
/etc/systemd/system/dbus-org.freedesktop.Avahi.service

journalctl
čec 13 21:15:10 brownie-desktop systemd[1]: NetworkManager-dispatcher.service: Deactivated successfully.
čec 13 21:15:09 brownie-desktop NetworkManager[13119]: <info>  [1783970109.3392] audit: op="statistics" interface="proton0" ifindex=11 args="0" pid=1158 uid=1000 res>
čec 13 21:15:09 brownie-desktop NetworkManager[13119]: <info>  [1783970109.3361] audit: op="statistics" interface="enp42s0" ifindex=13 args="0" pid=1158 uid=1000 res>
čec 13 21:15:09 brownie-desktop NetworkManager[13119]: <info>  [1783970109.3329] audit: op="statistics" interface="ipv6leakintrf0" ifindex=12 args="0" pid=1158 uid=1>
čec 13 21:15:08 brownie-desktop avahi-daemon[665]: Registering new address record for fe80::2bca:6877:97b0:29d1 on enp42s0.*.
čec 13 21:15:08 brownie-desktop avahi-daemon[665]: New relevant interface enp42s0.IPv6 for mDNS.
čec 13 21:15:08 brownie-desktop avahi-daemon[665]: Joining mDNS multicast group on interface enp42s0.IPv6 with address fe80::2bca:6877:97b0:29d1.
čec 13 21:15:07 brownie-desktop NetworkManager[13119]: <info>  [1783970107.0073] audit: op="statistics" interface="proton0" ifindex=11 args="2000" pid=1158 uid=1000 >
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.9699] device (enp42s0): Activation: successful, device activated.
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.9692] device (enp42s0): state change: secondaries -> activated (reason 'none', managed-typ>
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.9692] device (enp42s0): state change: ip-check -> secondaries (reason 'none', managed-type>
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.9676] device (enp42s0): state change: ip-config -> ip-check (reason 'none', managed-type: >
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.9442] policy: set 'Wired connection 1' (enp42s0) as default for IPv4 routing and DNS
čec 13 21:15:06 brownie-desktop avahi-daemon[665]: Registering new address record for 192.168.69.4 on enp42s0.IPv4.
čec 13 21:15:06 brownie-desktop avahi-daemon[665]: New relevant interface enp42s0.IPv4 for mDNS.
čec 13 21:15:06 brownie-desktop avahi-daemon[665]: Joining mDNS multicast group on interface enp42s0.IPv4 with address 192.168.69.4.
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.9432] dhcp4 (enp42s0): state changed new lease, address=192.168.69.4
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.8853] audit: op="statistics" interface="proton0" ifindex=11 args="2000" pid=1158 uid=1000 >
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.8792] audit: op="statistics" interface="ipv6leakintrf0" ifindex=12 args="2000" pid=1158 ui>
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.7783] dhcp4 (enp42s0): state changed new lease, address=192.168.69.4, acd pending
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.7687] dhcp4 (enp42s0): activation: beginning transaction (timeout in 45 seconds)
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.7683] device (enp42s0): state change: config -> ip-config (reason 'none', managed-type: 'f>
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.7664] device (enp42s0): state change: prepare -> config (reason 'none', managed-type: 'ful>
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.7663] device (enp42s0): state change: disconnected -> prepare (reason 'none', managed-type>
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.7663] device (enp42s0): Activation: starting connection 'Wired connection 1' (86d1868c-88a>
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.7661] policy: auto-activating connection 'Wired connection 1' (86d1868c-88a7-335b-8e79-078>
čec 13 21:15:06 brownie-desktop kernel: r8125: enp42s0: link up
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.7658] device (enp42s0): state change: unavailable -> disconnected (reason 'carrier-changed>
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.7783] dhcp4 (enp42s0): state changed new lease, address=192.168.69.4, acd pending
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.7687] dhcp4 (enp42s0): activation: beginning transaction (timeout in 45 seconds)
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.7683] device (enp42s0): state change: config -> ip-config (reason 'none', managed-type: 'f>
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.7664] device (enp42s0): state change: prepare -> config (reason 'none', managed-type: 'ful>
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.7663] device (enp42s0): state change: disconnected -> prepare (reason 'none', managed-type>
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.7663] device (enp42s0): Activation: starting connection 'Wired connection 1' (86d1868c-88a>
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.7661] policy: auto-activating connection 'Wired connection 1' (86d1868c-88a7-335b-8e79-078>
čec 13 21:15:06 brownie-desktop kernel: r8125: enp42s0: link up
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.7658] device (enp42s0): state change: unavailable -> disconnected (reason 'carrier-changed>
čec 13 21:15:06 brownie-desktop NetworkManager[13119]: <info>  [1783970106.7652] device (enp42s0): carrier: link connected
čec 13 21:15:03 brownie-desktop kernel: enp42s0: 0xffffcf4115770000, 2c:f0:5d:76:c7:ce, IRQ 41
čec 13 21:15:03 brownie-desktop NetworkManager[13119]: <info>  [1783970103.5854] device (enp42s0): state change: unmanaged -> unavailable (reason 'managed', managed->
čec 13 21:15:03 brownie-desktop kernel: r8125 0000:2a:00.0 enp42s0: renamed from eth0
čec 13 21:15:03 brownie-desktop NetworkManager[13119]: <info>  [1783970103.5808] device (eth0): interface index 13 renamed iface from 'eth0' to 'enp42s0'
čec 13 21:15:03 brownie-desktop sudo[41167]: pam_unix(sudo:session): session closed for user root
čec 13 21:15:03 brownie-desktop NetworkManager[13119]: <info>  [1783970103.5707] manager: (eth0): new Ethernet device (/org/freedesktop/NetworkManager/Devices/5)
čec 13 21:15:03 brownie-desktop kernel: r8125  Copyright (C) 2026 Realtek NIC software team <nicfae@realtek.com>
                                          This program comes with ABSOLUTELY NO WARRANTY; for details, please see <http://www.gnu.org/licenses/>.
                                          This is free software, and you are welcome to redistribute it under certain conditions; see <http://www.gnu.org/licenses/>.
čec 13 21:15:03 brownie-desktop kernel: r8125: This product is covered by one or more of the following patents: US6,570,884, US6,115,776, and US6,327,625.
čec 13 21:15:03 brownie-desktop kernel: r8125 Ethernet controller driver 9.018.00-NAPI-DASH loaded
čec 13 21:15:03 brownie-desktop sudo[41167]: pam_unix(sudo:session): session opened for user root(uid=0) by brownie(uid=1000)
čec 13 21:15:03 brownie-desktop sudo[41167]:  brownie : TTY=pts/9 ; PWD=/home/brownie ; USER=root ; COMMAND=/usr/bin/modprobe r8125
čec 13 21:15:00 brownie-desktop sudo[41128]: pam_unix(sudo:session): session closed for user root
čec 13 21:15:00 brownie-desktop systemd[1]: Started Network Manager Script Dispatcher Service.
čec 13 21:15:00 brownie-desktop systemd[1]: Starting Network Manager Script Dispatcher Service...
čec 13 21:15:00 brownie-desktop NetworkManager[13119]: <info>  [1783970100.3902] dhcp4 (enp42s0): state changed no lease
čec 13 21:15:00 brownie-desktop NetworkManager[13119]: <info>  [1783970100.3902] dhcp4 (enp42s0): activation: beginning transaction (timeout in 45 seconds)
čec 13 21:15:00 brownie-desktop NetworkManager[13119]: <info>  [1783970100.3902] dhcp4 (enp42s0): canceled DHCP transaction
čec 13 21:15:00 brownie-desktop NetworkManager[13119]: <info>  [1783970100.3901] device (enp42s0): state change: activated -> unmanaged (reason 'unmanaged-link-not-i>
čec 13 21:15:00 brownie-desktop avahi-daemon[665]: Withdrawing address record for 192.168.69.4 on enp42s0.
čec 13 21:15:00 brownie-desktop avahi-daemon[665]: Withdrawing address record for fe80::2bca:6877:97b0:29d1 on enp42s0.
čec 13 21:15:00 brownie-desktop avahi-daemon[665]: Leaving mDNS multicast group on interface enp42s0.IPv4 with address 192.168.69.4.
čec 13 21:15:00 brownie-desktop avahi-daemon[665]: Interface enp42s0.IPv4 no longer relevant for mDNS.
čec 13 21:15:00 brownie-desktop avahi-daemon[665]: Leaving mDNS multicast group on interface enp42s0.IPv6 with address fe80::2bca:6877:97b0:29d1.
čec 13 21:15:00 brownie-desktop avahi-daemon[665]: Interface enp42s0.IPv6 no longer relevant for mDNS.

Mellow · July 15, 2026, 10:01am

Just a shot in the dark, is your bios/firmware for your motherboard updated all the way?
Sometimes that is needed else the Ethernet port doesn’t work correctly or at all.
Often when you go to the vendors website for bios updates there is a section for the Ethernet port, if you didn’t install it you may want to do it.

Apart from that according to your inxi it seems you have 2 network cards? One of which doesn’t have a driver… Did you verify that you are plugged into the correct one?

tbg · July 15, 2026, 7:16pm

Hate to be so blatantly obvious, but 90% of Ethernet issues end up being related to subpar cabling.

Have you tried a more robust ethernet cable such as cat 7?

Also, have you tried different ports on your router?

Brownie · July 15, 2026, 8:21pm

Hi, so, I updated the bios today, with high hopes, and now I came back to my PC few hours later and it’s not working again. It’s always like that, it starts working, then I turn it off for some hours and when I come back it doesn’t work again. Also, the wifi and ethernet works on all my other devices, so I 100% believe it must be some device issue.

I have it plugged in the correct port, and even trying the other one doesn’t change anything.

Last thing, out of desperation I tried different distro, so I am on Bazzite instead of Endeavour, so I am not sure if I can expect help here.. But if anyone has some other idea that could work no matter the distro I would greatly appreciate it ^^

Thank you

Brownie · July 15, 2026, 8:22pm

I have actually tried another cable, as well as different ports and it didn’t help at all. Not even for a little bit, it stayed the exact same. The only reliable thing to make it work currently is the rmmod and modprobe I mentioned above, which leads me to a driver issue… Just can’t solve that issue itself…

Mellow · July 15, 2026, 8:45pm

The only other thing I can think of right now is energy efficient Ethernet that could be the issue…

I don’t know much about it, maybe you can read into it if that could be related or is similar to your issue

Brownie · July 15, 2026, 9:35pm

I am currently trying to use the other ethernet adapter on my PC, since it has a different ethernet chip and perhaps the drivers and kernel like it more But in case the issue comes back again, I’ll try what you’ve came up with here

tbg · July 16, 2026, 9:34pm

If you want to switch to your r8168 Ethernet adapter then you will need to install the proprietary r8168 DKMS driver, or remove the blacklist on r8169 to use the in-kernel r8169 kernel module.

Brownie · July 17, 2026, 8:13am

Thank you! Since I installed a new distro, I don’t actually need to remove the blacklist, and it seems to be working now in the second port!
For anyone having this problem in the future, I think the proprietary DKMS drivers are one option, that I was also considering if this “workaround” I have didn’t work. Then I would of course try the things mentioned in this thread:

Update BIOS
Try disabling EEE
Change Ethernet cable and/or the ethernet port in router
If you have the RTL8125 chip, you could also try getting the driver from RealTek website, this has not worked for me tho
Lastly, if you have the option, try different ethernet port on your PC, since this is most definitely driver issue, and the other port could have different chip which doesn’t have driver issues.. I have also tried this before, but when the ethernet was down already, changing the port didn’t actually help, it only started working when the ethernet was up and I changed the port!

Thank you everyone for your help!!