Robtex

Up: 67.52.40.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 67.52.40.0/23
Down right: 67.52.42.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
67.52.40.158	A	rrcs-67-52-40-158.west.biz.rr.com
67.52.42.2	A	mail.expertune.com
67.52.42.4	PTR	rrcs-67-52-42-4.west.biz.rr.com
67.52.42.4	A	plantriage.com
67.52.42.4	A	www.expertune.com
67.52.42.58	A	mail.techmasterinc.com
67.52.42.84	A+PTR	rrcs-67-52-42-84.west.biz.rr.com
67.52.42.106	A	ns4.rhinosoft.com
67.52.42.106	A	ns2.rhinosoft.com
67.52.42.109	A	mail5.rhinosoft.com
67.52.42.150	PTR	rrcs-67-52-42-150.west.biz.rr.com
67.52.42.194	A	hmgraphicsprep.com
67.52.43.10	A+PTR	mail.lacrosselitho.com
67.52.43.10	A+PTR	mail.printmosaica.com
67.52.43.10	A	mail2.wrap-r-ator.com
67.52.43.50	PTR	mail.itemamerica.com
67.52.43.50	PTR	mail.itemnorthamerica.com
67.52.43.51	PTR	rrcs-67-52-43-51.west.biz.rr.com
67.52.43.51	A	mail.itemamerica.com
67.52.43.51	A	mail.mbkit.com
67.52.43.77	PTR	mail.ramart.org
67.52.43.98	A+PTR	rrcs-67-52-43-98.west.biz.rr.com
67.52.43.98	A	instanthealthcare.net
67.52.43.101	A	procaremed.com
67.52.43.138	A	mail.ambeng.com
67.52.43.138	A	ambeng.com
67.52.43.163	A+PTR	rrcs-67-52-43-163.west.biz.rr.com
67.52.43.164	A	rrcs-67-52-43-164.west.biz.rr.com
67.52.43.165	A+PTR	lightsp.franklin.k12.wi.us
67.52.43.165	A	rrcs-67-52-43-165.west.biz.rr.com
67.52.43.183	A+PTR	rrcs-67-52-43-183.west.biz.rr.com
67.52.43.183	A	franklinsabers.org
67.52.43.183	A	franklinpublicschools.org
67.52.43.187	A	ps.franklin.k12.wi.us
67.52.43.188	PTR	franklin.k12.wi.us
67.52.43.188	A	mail.franklin.k12.wi.us
67.52.43.210	A	mail.hydra-seal.com
67.52.43.214	A	mail-rr.forwardua.com
67.52.43.226	A+PTR	rrcs-67-52-43-226.west.biz.rr.com
67.52.43.228	A+PTR	smtp.osthoff.com