Robtex

Up: 66.151.48.0/20
Can't show all results, try to descend to a more specific CIDR
Down left: 66.151.56.0/22
Down right: 66.151.60.0/22
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
66.151.56.65	PTR	smtp.emailpros.com
66.151.57.2	PTR	gms1.gmsnet.com
66.151.57.3	A	limbo1.gmsnet.com
66.151.57.12	A	oldmail.gmsnet.com
66.151.57.15	A	mail.medicalfood.org
66.151.57.15	A	mail.whitecserum.com
66.151.57.15	A	mail.denstea.com
66.151.57.18	PTR	ninjastreetmarks.net
66.151.57.18	A	taisystem.com
66.151.57.32	A	autofreak.net
66.151.57.61	A	software4research.com
66.151.57.65	A	socialrewards.com
66.151.57.72	PTR	seasidewomen.net
66.151.57.72	A	denstea.com
66.151.57.73	PTR	seasidewomen.net
66.151.57.96	PTR	dress-queen.us
66.151.57.120	A	anagift.com
66.151.57.120	A	www.anagift.com
66.151.58.11	A	tripamericaonline.com
66.151.58.101	A	placesugo.com
66.151.59.5	PTR	ewtllc.com
66.151.59.101	PTR	bull.ewtllc.com
66.151.59.102	PTR	bear.ewtllc.com
66.151.61.53	A	publisherfederation.net
66.151.61.53	A	publisherfederation.org
66.151.61.53	A	pubfederation.com
66.151.61.54	PTR	es-mta.rubiconproject.com
66.151.61.57	PTR	login57.rubiconproject.com
66.151.61.57	A	dpgdemo.com
66.151.61.141	A	qa.rubiconproject.com
66.151.61.145	A	newsletter.rubiconproject.com
66.151.62.146	A	gguhdamcejwqj.com
66.151.63.8	PTR	mail.marketscan.com
66.151.63.140	A	ns1.riotgames.com
66.151.63.140	A	ns1.leagueoflegends.com
66.151.63.152	PTR	laxweb3.riotgames.com
66.151.63.154	A	store.leagueoflegends.com
66.151.63.180	A+PTR	mx3.riotgames.com
66.151.63.190	PTR	border1.ge3-35.riotgames-16.lax007.pnap.net