Robtex

Up: 81.0.214.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 81.0.215.0/25
Down right: 81.0.215.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
81.0.215.0	PTR	casablanca-net.casablanca.cz
81.0.215.2	PTR	assigned-81-0-215-002.casablanca.cz
81.0.215.4	A+PTR	ms.amoscz.cz
81.0.215.7	PTR	bcast-81-0-215-007.casablanca.cz
81.0.215.8	PTR	net-81-0-215-008.casablanca.cz
81.0.215.16	PTR	net-81-0-215-016.casablanca.cz
81.0.215.23	PTR	bcast-81-0-215-023.casablanca.cz
81.0.215.24	PTR	net-81-0-215-024.casablanca.cz
81.0.215.31	PTR	unassigned-81-0-215-031.casablanca.cz
81.0.215.32	PTR	net-81-0-215-032.casablanca.cz
81.0.215.35	A+PTR	server.zena-in.cz
81.0.215.39	PTR	bcast-81-0-215-039.casablanca.cz
81.0.215.40	PTR	net-81-0-215-040.casablanca.cz
81.0.215.47	PTR	bcast-81-0-215-047.casablanca.cz
81.0.215.48	PTR	net-81-0-215-048.casablanca.cz
81.0.215.50	PTR	assigned-81-0-215-050.casablanca.cz
81.0.215.50	A	faco.cz
81.0.215.50	A	hotelhanoi.cz
81.0.215.55	PTR	bcast-81-0-215-055.casablanca.cz
81.0.215.56	PTR	net-81-0-215-056.casablanca.cz
81.0.215.57	A	remote.zelivskaprovozni.cz
81.0.215.57	A	remote.zelivska.cz
81.0.215.64	PTR	net-81-0-215-064.casablanca.cz
81.0.215.65	A+PTR	mail.nowatron.cz
81.0.215.71	PTR	bcast-81-0-215-071.casablanca.cz
81.0.215.72	PTR	net-81-0-215-072.casablanca.cz
81.0.215.79	PTR	bcast-81-0-215-079.casablanca.cz
81.0.215.80	PTR	net-81-0-215-080.casablanca.cz
81.0.215.87	PTR	bcast-81-0-215-087.casablanca.cz
81.0.215.88	PTR	net-81-0-215-088.casablanca.cz
81.0.215.95	PTR	bcast-81-0-215-095.casablanca.cz
81.0.215.96	PTR	net-81-0-215-096.casablanca.cz
81.0.215.109	PTR	assigned-81-0-215-109.casablanca.cz
81.0.215.109	A	exchange.dojacek.cz
81.0.215.136	PTR	net-81-0-215-136.casablanca.cz
81.0.215.194	PTR	assigned-81-0-215-194.casablanca.cz
81.0.215.200	PTR	net-81-0-215-200.casablanca.cz
81.0.215.201	A	gradasmtp.casablanca.cz
81.0.215.227	PTR	assigned-81-0-215-227.casablanca.cz
81.0.215.227	A	mail.gordion.cz
81.0.215.227	A	mail.gordionservices.com
81.0.215.228	PTR	assigned-81-0-215-228.casablanca.cz
81.0.215.228	A	mgw2.gordion.cz
81.0.215.228	A	mgw.gordion.cz
81.0.215.232	PTR	net-81-0-215-232.casablanca.cz