Robtex

Up: 212.21.40.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 212.21.40.0/25
Down right: 212.21.40.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
212.21.40.22	PTR	static-22.40.21.212.in-addr.arpa
212.21.40.35	PTR	static-35.40.21.212.in-addr.arpa
212.21.40.39	PTR	static-39.40.21.212.in-addr.arpa
212.21.40.54	PTR	static-54.40.21.212.in-addr.arpa
212.21.40.54	A	mail.togosh.com
212.21.40.66	PTR	static-66.40.21.212.in-addr.arpa
212.21.40.72	PTR	static-72.40.21.212.in-addr.arpa
212.21.40.79	PTR	static-79.40.21.212.in-addr.arpa
212.21.40.80	PTR	static-80.40.21.212.in-addr.arpa
212.21.40.96	PTR	static-96.40.21.212.in-addr.arpa
212.21.40.200	PTR	static-200.40.21.212.in-addr.arpa
212.21.40.202	PTR	static-202.40.21.212.in-addr.arpa
212.21.40.220	PTR	static-220.40.21.212.in-addr.arpa
212.21.40.220	A	newforum.chickenkiller.com
212.21.40.220	A	auberdine.etowns.net
212.21.40.223	PTR	static-223.40.21.212.in-addr.arpa
212.21.40.244	PTR	static-244.40.21.212.in-addr.arpa