Robtex

Up: 117.4.16.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 117.4.20.0/23
Down right: 117.4.22.0/23

IP	Type	Hostname
117.4.20.2	PTR	localhost
117.4.20.28	PTR	localhost
117.4.20.69	PTR	localhost
117.4.20.107	PTR	localhost
117.4.20.244	PTR	localhost
117.4.21.248	PTR	localhost
117.4.22.5	PTR	localhost
117.4.22.35	PTR	localhost
117.4.22.36	PTR	localhost
117.4.22.53	PTR	localhost
117.4.22.58	PTR	localhost
117.4.22.129	PTR	localhost
117.4.22.132	PTR	localhost
117.4.22.147	PTR	localhost
117.4.22.157	PTR	localhost
117.4.22.210	PTR	localhost
117.4.22.230	PTR	localhost
117.4.22.243	PTR	localhost
117.4.22.247	PTR	localhost
117.4.22.254	PTR	localhost
117.4.23.14	PTR	localhost
117.4.23.45	PTR	localhost
117.4.23.50	PTR	localhost
117.4.23.188	PTR	localhost
117.4.23.205	PTR	localhost