Created attachment 693890 [details]
all logs from /var/log/YaST2

zypper dup from 13.2 to leap42.1 changes the ether names from enpXsX back to
ethX but does not update network config.

system is a KVM host, 32GB, 8core AMD, one rtl and two intel gbit cards.

I updated from 13.1 to 13.2 without issue.
rebooted, all was well
I then updated from 13.2 to leap42.1

all enpXs0 ETHER devices ( i have three network cards in this machine)
were renamed to old-style ethX

but the ifcfg-* files were not updated, resulting in non-reachability, no
network

fortunately I had a serial terminal, installed because of previous problems
with
networking (when configuring a bridge, it looses it already configured devices,
this is one of the bugs we have in suse since 13.1, very annoying. ) 

this costs a lot of time, friends :-)