Robtex

Up: 72.52.40.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 72.52.40.0/23
Down right: 72.52.42.0/23

IP	Type	Hostname
72.52.40.23	PTR	unknown.prolexic.com
72.52.40.30	PTR	unknown.prolexic.com
72.52.40.41	PTR	unknown.prolexic.com
72.52.40.76	PTR	unknown.prolexic.com
72.52.40.140	PTR	a72-52-40-140.deploy.static.akamaitechnologies.com
72.52.40.225	PTR	unknown.prolexic.com
72.52.40.228	PTR	unknown.prolexic.com
72.52.41.52	PTR	unknown.prolexic.com
72.52.41.78	PTR	unknown.prolexic.com
72.52.41.96	PTR	unknown.prolexic.com
72.52.41.125	PTR	unknown.prolexic.com
72.52.41.127	PTR	unknown.prolexic.com
72.52.42.1	PTR	unknown.prolexic.com
72.52.42.155	PTR	unknown.prolexic.com
72.52.43.13	PTR	unknown.prolexic.com
72.52.43.24	PTR	unknown.prolexic.com
72.52.43.39	PTR	unknown.prolexic.com
72.52.43.68	PTR	unknown.prolexic.com
72.52.43.74	PTR	unknown.prolexic.com
72.52.43.86	PTR	unknown.prolexic.com
72.52.43.90	PTR	a72-52-43-90.deploy.static.akamaitechnologies.com
72.52.43.111	PTR	unknown.prolexic.com
72.52.43.123	PTR	unknown.prolexic.com
72.52.43.125	PTR	unknown.prolexic.com
72.52.43.139	PTR	unknown.prolexic.com
72.52.43.206	PTR	unknown.prolexic.com
72.52.43.225	PTR	unknown.prolexic.com