Robtex

Up: 192.72.0.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 192.72.0.0/23
Down right: 192.72.2.0/23

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
192.72.3.21	PTR	h21-192-72-3.seed.net.tw
192.72.3.22	PTR	h22-192-72-3.seed.net.tw
192.72.3.255	PTR	h255-192-72-3.seed.net.tw