Robtex

Up: 208.64.42.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 208.64.42.0/25
Down right: 208.64.42.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
208.64.42.29	A+PTR	autodiscover.sandata.com
208.64.42.29	A+PTR	sanexch2.sandata.com
208.64.42.29	A+PTR	sanexch1.sandata.com
208.64.42.51	PTR	datalineinc.com
208.64.42.51	PTR	integricor.com
208.64.42.51	PTR	ndsihealthcard.com