[SOLVED] NIC disappears after installing GPU

[MikeExMachina]

So my machine has single physical interface built into the motherboard which normally is at pci address 03:00 and gets a logical interface name "enp3s0". I'm trying to a add a 2nd gpu for video transcoding and after installing it, the NIC pci address changes to 04:00, and it stops getting assigned a logical interface (doesn't show up in ip addr with its old name or a new one). It does show up in lspci and lshw. I'm aware there is a debian bug related to renaming of network interfaces and I think I've been bit by it before while moving cards around, but I swear when that happened it just came up with a different logical name and I just had to reconfigure the bridge to use the new interface. Anybody ever seen something like this before?

 

[MikeExMachina]

As usual, the problem is between the keyboard and the chair, though I can't help but feel the whole thing could be a little more user friendly somehow. It turned out I was passing PCI 04:00 to a VM, so when the NIC got that address, it was no longer visible to the host. Disabled that passthrough, rebooted, NIC came up with a different logical address ("enp4s0") as I expected. Fixed /etc/network/interfaces to reflect that and I'm back up.