Thanks Porte ... learning on the fly
ifconfig -a
lo0: flags=1000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4> mtu 8232 index 1 inet 127.0.0.1 netmask ff000000
created a file /etc/hostname.lo0
Wrote the name of the machine I just made up -
ambush on the first line of the file.
reboot - Ok
ifconfig -a shows the same ?