Robtex

Up: 68.172.192.0/19
Can't show all results, try to descend to a more specific CIDR
Down left: 68.172.192.0/21
Down right: 68.172.200.0/21

IP	Type	Hostname
68.172.192.163	PTR	mta-68-172-192-163.maine.rr.com
68.172.192.192	PTR	mta-68-172-192-192.maine.rr.com
68.172.194.163	PTR	mta-68-172-194-163.maine.rr.com
68.172.195.36	PTR	mta-68-172-195-36.maine.rr.com
68.172.200.65	PTR	mta-68-172-200-65.maine.rr.com
68.172.203.209	PTR	mta-68-172-203-209.maine.rr.com
68.172.204.18	PTR	mta-68-172-204-18.maine.rr.com
68.172.204.87	PTR	mta-68-172-204-87.maine.rr.com
68.172.204.97	PTR	mta-68-172-204-97.maine.rr.com
68.172.204.242	PTR	mta-68-172-204-242.maine.rr.com