Linux kernel 4.4 starts using a mechanism called Network Predictable Naming for the network interfaces. It means the name of network interfaces is based on PCI addresses of the network adapters. For example, an adapter with PCI address 0003:01:00.0 would have a mapped network interface called enP3p1s0f0.
Due to recent changes on Linux kernel to better accommodate the Network Predictable naming in ppc64el architecture, users can possibly experience change in their network interfaces’ names on Ubuntu kernel upgrade to version 4.4.0-36 or subsequent versions.
The solution to this issue is to change the network interface name on file /etc/network/interfaces to fit the new name interface got after the kernel upgrade. After this, for all subsequent kernel versions >= 4.4.0-36 there will be no more naming modifications.
Notice however that booting from old kernel after changing the interface name will present the same issue again!
This issue appears when upgrading from old kernel to 4.4.0-36 and subsequent. Happens on Ubuntu 16.04 and 14.04.5 .
Hint: to show all network interfaces on your system, just issue ls -l /sys/class/net – it’ll show all the interfaces currently available and the symbolic link to their PCI devices.