Robtex

Up: 200.4.160.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 200.4.160.0/23
Down right: 200.4.162.0/23

IP	Type	Hostname
200.4.160.128	PTR	client-192-128.hainet.net
200.4.161.23	PTR	client-161-23.hainet.net
200.4.161.41	PTR	client-161-41.hainet.net
200.4.161.45	PTR	client-161-45.hainet.net
200.4.162.8	PTR	client-162-8.hainet.net
200.4.163.94	PTR	client-163-94.hainet.net
200.4.163.234	PTR	client-163-234.hainet.net