Robtex

Up: 72.221.0.0/20
Can't show all results, try to descend to a more specific CIDR
Down left: 72.221.0.0/22
Down right: 72.221.4.0/22
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
72.221.0.131	A	ataacec805e7a69.mm.pn.at.cox.net
72.221.4.15	PTR	wsip-72-221-4-15.dc.dc.cox.net
72.221.4.15	A	honestyandethics.com
72.221.4.15	A	easystonecenter.com
72.221.4.72	A	*.goldbeltraven.com
72.221.4.72	A	goldbeltmaster.goldbeltraven.com
72.221.4.72	A	mailhost.goldbeltraven.com
72.221.4.112	A+PTR	mail.br-envision.com
72.221.4.151	A+PTR	wsip-72-221-4-151.dc.dc.cox.net
72.221.4.151	A	mx.it-techservice.com
72.221.4.151	A	*.it-techservice.com
72.221.5.106	A+PTR	wsip-72-221-5-106.dc.dc.cox.net
72.221.5.106	A	washingtondoc.com
72.221.5.106	A	mail.norvarhealthservices.com
72.221.5.107	PTR	wsip-72-221-5-107.dc.dc.cox.net
72.221.5.215	A+PTR	wsip-72-221-5-215.dc.dc.cox.net
72.221.6.60	A	mail.rrtmail.com
72.221.6.60	A	mail2.wilbell.com
72.221.6.206	A+PTR	wsip-72-221-6-206.dc.dc.cox.net
72.221.6.206	A	myverisolv.com
72.221.7.3	A+PTR	wsip-72-221-7-3.dc.dc.cox.net
72.221.7.3	A	mail.jamaheatingandcooling.com
72.221.7.3	A	remote.jamaheatingandcooling.com
72.221.7.66	A	mail.systemsdefinition.com