Robtex

Up: 221.134.32.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 221.134.32.0/23
Down right: 221.134.34.0/23

IP	Type	Hostname
221.134.33.0	PTR	221-134-33-0.sify.net
221.134.33.255	PTR	221-134-33-255.sify.net
221.134.35.0	PTR	221-134-35-0.sify.net
221.134.35.2	PTR	221-134-35-2.sify.net
221.134.35.255	PTR	221-134-35-255.sify.net