Robtex

Up: 66.47.240.0/20
Can't show all results, try to descend to a more specific CIDR
Down left: 66.47.248.0/22
Down right: 66.47.252.0/22

IP	Type	Hostname
66.47.248.106	A	mail.fatwreck.com
66.47.248.215	A	user-112vu6n.biz.mindspring.com
66.47.254.3	PTR	home.maeckel.net
66.47.254.178	A	user-112vvli.biz.mindspring.com
66.47.255.255	A	user-112vvvv.biz.mindspring.com