Robtex

Up: 216.48.96.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 216.48.100.0/23
Down right: 216.48.102.0/23

IP	Type	Hostname
216.48.102.28	PTR	mta1.send.crisiseducation.com
216.48.102.60	PTR	mta1.goinsmail.com
216.48.102.65	PTR	mta2.americanacademytraining.com
216.48.102.68	PTR	mta1.alternativeantriebe.com
216.48.102.69	PTR	mta2.alternativeantriebe.com
216.48.102.70	PTR	mta3.alternativeantriebe.com
216.48.102.71	PTR	mta4.alternativeantriebe.com