Robtex

Up: 66.64.8.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 66.64.12.0/23
Down right: 66.64.14.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
66.64.12.34	A	smtp.goldmetal.com
66.64.12.34	A	mail.goldmetal.com
66.64.12.86	A	remote.universaltx.com
66.64.12.111	PTR	111-12-64.66.static.logixcom.net
66.64.12.117	PTR	117-12-64.66.static.logixcom.net
66.64.12.130	PTR	mail.taxease.com
66.64.12.132	A+PTR	mail.taxease.com
66.64.12.146	A	gw2.benenatilaw.com
66.64.12.146	A	gw1.benenatilaw.com
66.64.13.0	PTR	0-13-64.66.static.logixcom.net
66.64.13.8	PTR	8-13-64.66.static.logixcom.net
66.64.13.8	A	8-13-64.66.res.logixcom.net
66.64.13.29	PTR	29-13-64.66.static.logixcom.net
66.64.13.30	PTR	30-13-64.66.static.logixcom.net
66.64.13.30	A	30-13-64.66.res.logixcom.net
66.64.13.34	A	mail.groupholdings.net
66.64.13.62	PTR	62-13-64.66.static.logixcom.net
66.64.13.62	A	62-13-64.66.res.logixcom.net
66.64.13.71	PTR	71-13-64.66.static.logixcom.net
66.64.13.71	A	czset.com
66.64.13.91	PTR	91-13-64.66.static.logixcom.net
66.64.13.91	A	91-13-64.66.res.logixcom.net
66.64.13.114	A	mail.bsjpc.com
66.64.13.178	A	qpmrpa.com
66.64.13.178	A	ns2.box.qpmrpa.com
66.64.13.178	A	box.qpmrpa.com
66.64.13.186	PTR	186-13-64.66.static.logixcom.net
66.64.13.186	A	mail.suggslawfirm.com
66.64.14.50	PTR	mail.ascensiongroup.biz
66.64.14.84	PTR	84-14-64.66.static.logixcom.net
66.64.14.102	A	mail.ecc12.com
66.64.14.106	PTR	106-14-64.66.static.logixcom.net
66.64.14.106	A	remote.b3bm.com
66.64.14.106	A	b3bm.com
66.64.14.113	PTR	113-14-64.66.static.logixcom.net
66.64.14.114	A	rapp.realtyapp.com
66.64.14.130	A	balancedcoil.net
66.64.14.147	A	nwyc-mobile.net
66.64.14.203	A	mail.mccullough-group.com
66.64.14.242	A+PTR	smtp.zekomedia.com
66.64.14.242	A	zekomedia.com
66.64.14.242	A	www.zekomedia.com
66.64.14.244	A	mail.winkelmann.com
66.64.15.5	A	5-15-64.66.res.logixcom.net
66.64.15.9	A	9-15-64.66.res.logixcom.net
66.64.15.19	PTR	19-15-64.66.static.logixcom.net
66.64.15.29	A	29-15-64.66.res.logixcom.net
66.64.15.34	PTR	mail.mycompasschurch.com
66.64.15.66	PTR	66-15-64.66.static.logixcom.net
66.64.15.70	PTR	70-15-64.66.static.logixcom.net
66.64.15.75	PTR	75-15-64.66.static.logixcom.net
66.64.15.75	A	office365-ppe.telligent.org
66.64.15.75	A	office365r2.telligent.org
66.64.15.81	A	81-15-64.66.res.logixcom.net
66.64.15.82	A	82-15-64.66.res.logixcom.net
66.64.15.146	PTR	146-15-64.66.static.logixcom.net
66.64.15.146	A	mail2.jdmartin.com
66.64.15.158	A	mail.genesisresources.com
66.64.15.188	PTR	mail.unlimitedsprinkler.net
66.64.15.196	PTR	196-15-64.66.static.logixcom.net
66.64.15.196	A	ejsmithenterprises.com
66.64.15.230	A	mail.lustiglawfirm.com
66.64.15.244	A	244-15-64.66.res.logixcom.net
66.64.15.250	PTR	email.servmartinc.com