Robtex

Up: 203.101.0.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 203.101.0.0/23
Down right: 203.101.2.0/23

IP	Type	Hostname
203.101.1.4	PTR	dsl.delhi.004.1.101.203.airtelbroadband.in
203.101.1.6	PTR	dsl.delhi.006.1.101.203.airtelbroadband.in
203.101.1.63	PTR	dsl.delhi.063.1.101.203.airtelbroadband.in
203.101.1.131	PTR	dsl.delhi.131.1.101.203.airtelbroadband.in
203.101.3.164	PTR	dsl.delhi.164.3.101.203.airtelbroadband.in