Robtex

Up: 194.64.192.0/18
Can't show all results, try to descend to a more specific CIDR
Down left: 194.64.192.0/20
Down right: 194.64.208.0/20
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
194.64.220.16	A+PTR	nsx.bauboden.com
194.64.220.17	PTR	ns1.aareon-ag.com
194.64.220.17	PTR	mail3.aareon.com
194.64.220.17	PTR	ns1.aareon.com
194.64.220.20	PTR	mail4.aareon.com
194.64.220.20	PTR	ns3.aareon.com
194.64.220.20	PTR	gate2.bauboden.com