Robtex

Up: 206.81.64.0/20
Can't show all results, try to descend to a more specific CIDR
Down left: 206.81.64.0/22
Down right: 206.81.68.0/22
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
206.81.64.21	A	ns1.4dvision.com
206.81.64.22	A	ns2.4dvision.com
206.81.67.36	A+PTR	ftpswrd.llvresort.com
206.81.67.114	A	ns3.isc4you.com
206.81.67.114	A	ns3.rentersvoice.info
206.81.67.114	A	ns3.netmail.ws