pfsense vm: WAN NIC passthrough issue with 2.5G connection to fiber router

[MrLou]

Hi all,

I'm encountering an issue with my Proxmox setup where a WAN NIC passed through to a pfSense VM stops working after around 2000 pings. To restore connectivity, I need to access the pfSense interface, navigate to the NIC settings, and click "Apply" without making any changes. This seems to reset the port, and it starts working again.

Here’s a summary of my setup:

• Proxmox version: 8.3.1
• pfSense version:2.7.2
• NIC details: 02:00.0 Ethernet controller: Intel Corporation Ethernet Controller I225-V (rev 03) with passthrough configured for the WAN interface
• WAN connection: 2.5G Ethernet connected to a fiber router
• Behaviour: WAN works fine initially but stops responding after ~2000 pings. The issue resolves temporarily after applying changes to the NIC in pfSense.

I've checked the following:

1. Proxmox passthrough configuration seems correct, as the NIC is recognized and functional in the pfSense VM.
2. pfSense logs show no clear indication of why the WAN connection drops.
3. The issue is reproducible consistently, and other NICs on the Proxmox server don’t exhibit this behaviour.

My questions:

1. Has anyone encountered a similar issue with Intel I225-V NICs or passthrough configurations?
2. Could this be related to Proxmox, pfSense, or potential compatibility issues with the 2.5G fiber router?
3. Are there specific troubleshooting steps or logs I should look into on the Proxmox side to narrow down the cause?

Any advice or pointers would be greatly appreciated. Let me know if more details are needed.

Thanks in advance!