Robtex

Up: 72.171.48.0/20
Can't show all results, try to descend to a more specific CIDR
Down left: 72.171.56.0/22
Down right: 72.171.60.0/22

IP	Type	Hostname
72.171.57.10	PTR	host72171001057.direcway.com
72.171.57.80	PTR	host72171008057.direcway.com
72.171.57.81	PTR	host72171008157.direcway.com
72.171.57.137	PTR	host721710013757.direcway.com
72.171.57.152	PTR	host721710015257.direcway.com
72.171.57.160	PTR	host721710016057.direcway.com
72.171.57.177	PTR	host721710017757.direcway.com
72.171.57.202	PTR	host721710020257.direcway.com
72.171.57.233	PTR	host721710023357.direcway.com
72.171.57.243	PTR	host721710024357.direcway.com
72.171.57.248	PTR	host721710024857.direcway.com