Robtex

Up: 192.72.0.0/20
Can't show all results, try to descend to a more specific CIDR
Down left: 192.72.0.0/22
Down right: 192.72.4.0/22

IP	Type	Hostname
192.72.1.2	A	192.72.132-static.reverse.softlayer.com
192.72.2.5	A	192.72.205-static.reverse.softlayer.com
192.72.2.5	A	192.72.235-static.reverse.softlayer.com
192.72.2.6	A	192.72.226-static.reverse.softlayer.com
192.72.2.76	A	ns1.northmemorial.com
192.72.3.0	PTR	h0-192-72-3.seed.net.tw
192.72.3.2	PTR	h2-192-72-3.seed.net.tw
192.72.4.0	PTR	h0-192-72-4.seed.net.tw
192.72.4.2	PTR	h2-192-72-4.seed.net.tw
192.72.4.33	PTR	h33-192-72-4.seed.net.tw
192.72.4.74	PTR	h74-192-72-4.seed.net.tw
192.72.4.89	PTR	h89-192-72-4.seed.net.tw
192.72.4.91	PTR	h91-192-72-4.seed.net.tw
192.72.4.96	PTR	h96-192-72-4.seed.net.tw
192.72.4.115	PTR	h115-192-72-4.seed.net.tw
192.72.4.146	PTR	h146-192-72-4.seed.net.tw
192.72.4.171	PTR	h171-192-72-4.seed.net.tw
192.72.4.202	PTR	h202-192-72-4.seed.net.tw
192.72.4.203	PTR	h203-192-72-4.seed.net.tw
192.72.5.1	PTR	fido.net.tw