The Leap 42.1 Release Notes mention that an upgrade from 13.2 needs to prevent
the rename from (13.2) "predictable network interface names" to (Leap 42.1)
"persistent interface names". (Bug 953769)

There is however no note mentioning that after the upgrade has completed it is
advisable to use the Leap 42.1 default of "persistent interface names".
(/etc/udev/rules.d/70-persistent-net.rules should be removed.)

Additionally, after creating the new ifcfg files, the directory
/etc/sysconfig/network/ needs to be checked for any 13.2 ifcfg files needing
removal such as "ifcfg-enp2s0".