Single port on NIC randomly disconnecting

[Sakreton]

Hey,

i am running a 3 node PVE + Ceph Cluster on 3x Minesforum MS-A2.
The nodes are running identical hardware.

On one of the 3 nodes

At supposedly random times one 2.5Gbit Port on a RTL8125 2.5GbE Controller (rev 05) NIC disconnects.
The affected port is used for the guest traffic thats probably the only reason why i even noticed it in the first place lol.
All other NICs (2x Ceph), even the other port (used for Corosync to a different switch) on this NIC are not affected.

This also never occured on any other node.

I have tried a different Switch-Port and entire switch, its the host nic not the switch side.
I have also obviously rebooted this node.

I am running PVE 9.2.2, the problem persists for some time already since troubleshooting is a bit difficult since i can't force the problem to appear.

Any ideas before i approach minisforum any help or ideas are greatly appreciated! Thanks in advance and for reading this! :>

Proxmox Log:
May 27 20:07:44 prox-ganymede kernel: r8169 0000:03:00.0 nic0: Link is Down
May 27 20:07:44 prox-ganymede kernel: vmbr0: port 1(nic0) entered disabled state
May 27 20:07:52 prox-ganymede kernel: r8169 0000:03:00.0 nic0: Link is Up - 2.5Gbps/Full - flow control off
May 27 20:07:52 prox-ganymede kernel: vmbr0: port 1(nic0) entered blocking state
May 27 20:07:52 prox-ganymede kernel: vmbr0: port 1(nic0) entered forwarding state
May 27 20:07:54 prox-ganymede kernel: r8169 0000:03:00.0 nic0: Link is Down
May 27 20:07:54 prox-ganymede kernel: vmbr0: port 1(nic0) entered disabled state
May 27 20:07:55 prox-ganymede pvestatd[1566]: PBS_VM: error fetching datastores - 500 Can't connect to PBS:8007 (Connection timed out)
May 27 20:07:55 prox-ganymede pvestatd[1566]: status update time (7.093 seconds)
May 27 20:07:56 prox-ganymede kernel: r8169 0000:03:00.0 nic0: Link is Up - 1Gbps/Full - flow control off
May 27 20:07:56 prox-ganymede kernel: vmbr0: port 1(nic0) entered blocking state
May 27 20:07:56 prox-ganymede kernel: vmbr0: port 1(nic0) entered forwarding state
May 27 20:08:00 prox-ganymede kernel: r8169 0000:03:00.0 nic0: Link is Down
May 27 20:08:00 prox-ganymede kernel: vmbr0: port 1(nic0) entered disabled state
May 27 20:08:04 prox-ganymede kernel: r8169 0000:03:00.0 nic0: Link is Up - 2.5Gbps/Full - flow control off
May 27 20:08:04 prox-ganymede kernel: vmbr0: port 1(nic0) entered blocking state
May 27 20:08:04 prox-ganymede kernel: vmbr0: port 1(nic0) entered forwarding state

Switch Log:
2026-05-27 20:07:41 interface,info ether3(TO_GANYMEDE) link down
2026-05-27 20:07:49 interface,info ether3(TO_GANYMEDE) link up (speed 2.5G, full duplex)
2026-05-27 20:07:51 interface,info ether3(TO_GANYMEDE) link down
2026-05-27 20:07:52 interface,info ether3(TO_GANYMEDE) link up (speed 2.5G, full duplex)
2026-05-27 20:07:55 interface,info ether3(TO_GANYMEDE) link down
2026-05-27 20:08:02 interface,info ether3(TO_GANYMEDE) link up (speed 2.5G, full duplex)

 

[pille99]

The r8169 network driver is notorious in Linux and Proxmox for causing exactly this type of flapping behavior under heavy load or bridging.

apt update
apt install -y pve-headers pve-kernel-helper pve-edk2-firmware dkms r8168-dkms

install differnt drivers

 

[AristonPost]

If it's just one out of three you might have a bad patch cable. Did you also try another patch cable?
Also, Minisforum boxes are known to thermal issues. Maybe this particular system gets hotter than the other two?

 

[Sakreton]

Thanks for the possible solutions!
I am trying them now, i will update this Post as soon as i know if something worked^^