Robtex

Up: 204.15.200.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 204.15.200.0/25
Down right: 204.15.200.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
204.15.200.0	PTR	ip-204-15-200-0.nlayer.net
204.15.200.5	PTR	ip-204-15-200-5.gtt.net
204.15.200.5	A	mail.globalinternetworking.com
204.15.200.5	A	asl.mypop2pop.com
204.15.200.7	PTR	ip-204-15-200-7.gtt.net
204.15.200.7	A	mail1.gt-t.net
204.15.200.7	A	mail2.globalinternetworking.com
204.15.200.18	PTR	portal1.gt-t.net
204.15.200.18	A	portal1.gtt.net
204.15.200.47	PTR	ip-204-15-200-47.gtt.net
204.15.200.102	A	ns01.pop2pop.net