Robtex

Up: 68.70.128.0/19
Can't show all results, try to descend to a more specific CIDR
Down left: 68.70.128.0/21
Down right: 68.70.136.0/21
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
68.70.128.0	PTR	68-70-128-0-bar.up.net
68.70.128.8	A	mail.massiemfg.com
68.70.128.43	PTR	68-70-128-43-bar.up.net
68.70.128.48	PTR	68-70-128-48-bar.up.net
68.70.128.158	PTR	68-70-128-158-bar.up.net
68.70.128.159	PTR	68-70-128-159-bar.up.net
68.70.128.246	PTR	68-70-128-246-bar.up.net
68.70.128.252	PTR	68-70-128-252-bar.up.net
68.70.129.23	PTR	68-70-129-23-bar.up.net
68.70.129.49	PTR	68-70-129-49-bar.up.net
68.70.129.59	PTR	68-70-129-59-bar.up.net
68.70.129.162	PTR	68-70-129-162-bar.up.net
68.70.130.10	PTR	68-70-130-10-bar.up.net
68.70.130.179	PTR	68-70-130-179-bar.up.net
68.70.130.181	PTR	68-70-130-181-bar.up.net
68.70.130.235	PTR	68-70-130-235-bar.up.net
68.70.131.67	PTR	68-70-131-67-bar.up.net
68.70.131.95	PTR	68-70-131-95-bar.up.net
68.70.131.149	PTR	68-70-131-149-bar.up.net
68.70.135.9	PTR	68-70-135-9-chas.up.net
68.70.135.219	PTR	68-70-135-219-chas.up.net
68.70.135.221	PTR	68-70-135-221-chas.up.net
68.70.136.4	PTR	68-70-128thru143-4.up.net
68.70.136.8	PTR	68-70-128thru143-8.up.net
68.70.136.59	PTR	68-70-128thru143-59.up.net
68.70.138.12	PTR	68-70-128thru143-12.up.net
68.70.138.15	A	mail.pentitle.net
68.70.138.23	PTR	68-70-128thru143-23.up.net
68.70.138.97	PTR	68-70-128thru143-97.up.net
68.70.139.4	PTR	68-70-128thru143-4.up.net
68.70.139.105	PTR	68-70-128thru143-105.up.net
68.70.139.135	PTR	68-70-128thru143-135.up.net
68.70.139.142	PTR	68-70-128thru143-142.up.net
68.70.139.165	PTR	68-70-128thru143-165.up.net
68.70.139.182	PTR	68-70-128thru143-182.up.net
68.70.140.13	A	mail.northernhardwoods.com
68.70.140.21	PTR	68-70-128thru143-21.up.net
68.70.140.21	A	mail.talonresearch.com
68.70.140.21	A	mail.hawktechinc.com
68.70.143.93	PTR	68-70-128thru143-93.up.net