Robtex

Up: 64.81.24.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 64.81.28.0/23
Down right: 64.81.30.0/23

IP	Type	Hostname
64.81.28.98	A	dsl081-028-098.sfo1.dsl.speakeasy.net
64.81.29.15	A	mail.idengines.net
64.81.30.131	PTR	dc1sf.doublefusion.com
64.81.30.224	PTR	dsl081-030-224.sfo1.dsl.speakeasy.net
64.81.30.226	PTR	dsl081-030-226.sfo1.dsl.speakeasy.net
64.81.30.227	PTR	mail.livedeal.com
64.81.31.61	PTR	dsl081-031-061.sfo1.dsl.speakeasy.net
64.81.31.69	A	filthykitty.com
64.81.31.243	A	dsl081-031-243.sfo1.dsl.speakeasy.net
64.81.31.255	A+PTR	dsl081-031-255.sfo1.dsl.speakeasy.net