Robtex

Up: 72.131.0.0/18
Can't show all results, try to descend to a more specific CIDR
Down left: 72.131.0.0/20
Down right: 72.131.16.0/20
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
72.131.0.172	PTR	cpe-72-131-0-172.wi.res.rr.com
72.131.0.226	A+PTR	cpe-72-131-0-226.wi.res.rr.com
72.131.0.237	A+PTR	cpe-72-131-0-237.wi.res.rr.com
72.131.0.237	A	wasteconnection.net
72.131.1.143	PTR	cpe-72-131-1-143.wi.res.rr.com
72.131.1.161	A+PTR	cpe-72-131-1-161.wi.res.rr.com
72.131.1.161	A	nncs.dnsalias.com
72.131.2.2	PTR	cpe-72-131-2-2.wi.res.rr.com
72.131.2.12	A+PTR	cpe-72-131-2-12.wi.res.rr.com
72.131.2.12	A	tspringer.com
72.131.2.243	A+PTR	cpe-72-131-2-243.wi.res.rr.com
72.131.3.19	A	voteoat.com
72.131.3.125	A+PTR	cpe-72-131-3-125.wi.res.rr.com
72.131.3.134	PTR	cpe-72-131-3-134.wi.res.rr.com
72.131.3.163	A+PTR	cpe-72-131-3-163.wi.res.rr.com
72.131.3.163	A	cbradley.net
72.131.4.40	A+PTR	cpe-72-131-4-40.wi.res.rr.com
72.131.4.40	A	mail.beutelroad.net
72.131.4.40	A	beutelroad.net
72.131.4.101	A+PTR	cpe-72-131-4-101.wi.res.rr.com
72.131.5.171	A+PTR	cpe-72-131-5-171.wi.res.rr.com
72.131.8.19	A+PTR	cpe-72-131-8-19.wi.res.rr.com
72.131.8.35	A+PTR	cpe-72-131-8-35.wi.res.rr.com
72.131.8.50	A+PTR	cpe-72-131-8-50.wi.res.rr.com
72.131.8.53	A+PTR	cpe-72-131-8-53.wi.res.rr.com
72.131.8.55	A+PTR	cpe-72-131-8-55.wi.res.rr.com
72.131.8.91	A+PTR	cpe-72-131-8-91.wi.res.rr.com
72.131.8.106	A+PTR	cpe-72-131-8-106.wi.res.rr.com
72.131.8.110	A+PTR	cpe-72-131-8-110.wi.res.rr.com
72.131.8.140	A+PTR	cpe-72-131-8-140.wi.res.rr.com
72.131.8.198	A+PTR	cpe-72-131-8-198.wi.res.rr.com
72.131.8.211	A+PTR	cpe-72-131-8-211.wi.res.rr.com
72.131.8.241	A+PTR	cpe-72-131-8-241.wi.res.rr.com
72.131.9.95	A+PTR	cpe-72-131-9-95.wi.res.rr.com
72.131.9.112	A+PTR	cpe-72-131-9-112.wi.res.rr.com
72.131.10.9	A+PTR	cpe-72-131-10-9.wi.res.rr.com
72.131.10.39	A+PTR	cpe-72-131-10-39.wi.res.rr.com
72.131.10.39	A	nicko88.com
72.131.10.39	A	mx.nicko88.com
72.131.10.68	PTR	cpe-72-131-10-68.wi.res.rr.com
72.131.12.181	PTR	cpe-72-131-12-181.wi.res.rr.com
72.131.12.250	A+PTR	cpe-72-131-12-250.wi.res.rr.com
72.131.16.97	A	riggedsecurity.com
72.131.16.234	A+PTR	cpe-72-131-16-234.wi.res.rr.com
72.131.16.234	A	rfsmanagement.com
72.131.17.87	PTR	cpe-72-131-17-87.wi.res.rr.com
72.131.17.190	A	mail.kestrel-safety.com
72.131.17.190	A	thehillpeople.org
72.131.17.190	A	ns.thehillpeople.org
72.131.17.232	A	mail.thesilenos.com
72.131.18.48	A	mail.planetpheelix.com
72.131.19.44	A	cpe-72-131-19-44.wi.res.rr.com
72.131.19.124	A	arcwebisode.com
72.131.19.124	A	narcissisticracing.com
72.131.19.236	PTR	cpe-72-131-19-236.wi.res.rr.com
72.131.19.236	A	mail.warrenheld.com
72.131.19.236	A	warrenheld.com
72.131.20.57	A	cpe-72-131-20-57.wi.res.rr.com
72.131.21.73	A+PTR	cpe-72-131-21-73.wi.res.rr.com
72.131.22.6	A+PTR	cpe-72-131-22-6.wi.res.rr.com
72.131.22.35	A+PTR	cpe-72-131-22-35.wi.res.rr.com
72.131.22.35	A	echogs.com
72.131.22.197	A+PTR	cpe-72-131-22-197.wi.res.rr.com
72.131.22.197	A	schieble.us
72.131.22.197	A	mail.itr325.com
72.131.24.2	A+PTR	cpe-72-131-24-2.wi.res.rr.com
72.131.24.98	PTR	cpe-72-131-24-98.wi.res.rr.com
72.131.24.98	A	myunifiedmessaging.com
72.131.24.98	A	mail.rn-computing.com
72.131.24.131	A+PTR	cpe-72-131-24-131.wi.res.rr.com
72.131.24.131	A	snpenterprise.com
72.131.24.158	PTR	cpe-72-131-24-158.wi.res.rr.com
72.131.25.136	A	cpe-72-131-25-136.wi.res.rr.com
72.131.26.2	A+PTR	cpe-72-131-26-2.wi.res.rr.com
72.131.26.66	A+PTR	cpe-72-131-26-66.wi.res.rr.com
72.131.26.97	A	mail.mindofmalecki.com
72.131.26.97	A	mail.aerotechnet.com
72.131.26.182	PTR	cpe-72-131-26-182.wi.res.rr.com
72.131.27.91	A+PTR	cpe-72-131-27-91.wi.res.rr.com
72.131.28.2	A+PTR	cpe-72-131-28-2.wi.res.rr.com
72.131.28.177	A	cw-linux.curiowarehouse.com