PCIe Device Passthrough: NIC Name Instability and MAC Pinning

My Proxmox node rebooted, and suddenly the host was unreachable via SSH. I had to plug in a physical monitor and keyboard only to find that my primary network interface, which had been enp4s0 for months, had decided to rename itself to enp5s0 . Because my /etc/network/interfaces file was explicitly tied to enp4s0 , the bridge didn't come up, the IP wasn't assigned, and I was locked out of my own hardware. What I expected I expected the Linux kernel to consistently enumerate my PCIe devices. In a