My motherboard's built-in NIC is designated as 'enp5s0' when my system (Xubuntu 16.04) boots - or at least, it was.

I added a second Nvidia graphics card, and the NIC designation changed to 'enp6s0', which messed up my manual network config and the bridged network adaptor settings in VirtualBox.

I removed the second gpu, and the NIC reverted to 'enp5s0'.

I know the BIOS in my Gigabyte Z97X-SOC Force motherboard has some strange quirks relating to the NIC, so maybe this is just another BIOS bug.

I thought I'd check here, though, in case anyone knows of some other explanation, and any possible workarounds to allow the 'predictable network interface name' to be manually configured to avoid this problem in the future.

Pass to the kernel and it will be totally unpredictably always eth0.

Maybe one of these rules change it. https://access.redhat.com/documentat...Procedure.html