MACHINE 1:

# nslookup tibolli.net
;; Got SERVFAIL reply from 139.162.16.5, trying next server
;; Got SERVFAIL reply from 139.162.21.5, trying next server
Server:		139.162.27.5
Address:	139.162.27.5#53

** server can't find tibolli.net: SERVFAIL



Machine 2:

$ nslookup tibolli.net
Server:		192.168.100.1
Address:	192.168.100.1#53

Non-authoritative answer:
Name:	tibolli.net
Address: 139.162.20.246



Machine 3:

# nslookup tibolli.net
;; connection timed out; no servers could be reached