Robtex

Up: 200.50.26.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 200.50.27.0/25
Down right: 200.50.27.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
200.50.27.2	A+PTR	bermudez-longo.centennialpr.net
200.50.27.50	PTR	mail.prconvention.com
200.50.27.74	A+PTR	mail.horwathpr.com
200.50.27.74	A	horwathpr.com
200.50.27.74	A	staff.horwathpr.com
200.50.27.170	A	uh-dc1-mail.union-holdings.net