In my old diagnostic log (ifconfig) Eth0 shows this.
eth0: flags=6211<UP,BROADCAST,RUNNING,SLAVE,MULTICAST> mtu 1500
ether c4:34:6b:b7:13:f4 txqueuelen 1000 (Ethernet)
RX packets 4054501 bytes 3942148867 (3.6 GiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 2562515 bytes 1002392396 (955.9 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 16
In new log it shows this were Eth0 was.
gre0: flags=128<NOARP> mtu 1476
unspec 00-00-00-00-00-00-A8-1C-00-00-00-00-00-00-00-00 txqueuelen 1000 (UNSPEC)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0