shell:$ nslookup -timeout=2 -retry=1 'o.facebook.com'
Server:		75.98.161.224
Address:	75.98.161.224#53

Non-authoritative answer:
o.facebook.com	canonical name = 0.facebook.com.
0.facebook.com	canonical name = z-m.facebook.com.
z-m.facebook.com	canonical name = z-m.c10r.facebook.com.
Name:	z-m.c10r.facebook.com
Address: 57.144.172.6
Name:	z-m.c10r.facebook.com
Address: 2a03:2880:f356:6:face:b00c:0:14c9