Robtex

Up: 172.245.48.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 172.245.48.0/23
Down right: 172.245.50.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
172.245.48.1	PTR	host.colocrossing.com
172.245.48.10	PTR	172-245-48-10-host.colocrossing.com
172.245.48.14	PTR	host.colocrossing.com
172.245.48.31	PTR	172-245-48-31-host.colocrossing.com
172.245.48.32	PTR	172-245-48-32-host.colocrossing.com
172.245.48.42	PTR	172-245-48-42-host.colocrossing.com
172.245.48.46	PTR	172-245-48-46-host.colocrossing.com
172.245.48.54	PTR	host.colocrossing.com
172.245.48.60	PTR	host.colocrossing.com
172.245.48.69	PTR	172-245-48-69-host.colocrossing.com
172.245.48.85	PTR	host.colocrossing.com
172.245.48.107	PTR	172-245-48-107-host.colocrossing.com
172.245.48.137	PTR	host.colocrossing.com
172.245.48.162	PTR	host.colocrossing.com
172.245.48.168	PTR	host.colocrossing.com
172.245.48.180	PTR	172-245-48-180-host.colocrossing.com
172.245.48.213	PTR	172-245-48-213-host.colocrossing.com
172.245.48.238	PTR	172-245-48-238-host.colocrossing.com
172.245.49.66	A	coxcombablepar.com
172.245.49.66	A	uletplanarilyl.com
172.245.49.66	A	ldallssinewing.com
172.245.49.125	PTR	172-245-49-125-host.colocrossing.com
172.245.49.155	PTR	172-245-49-155-host.colocrossing.com
172.245.49.163	PTR	172-245-49-163-host.colocrossing.com
172.245.49.177	PTR	172-245-49-177-host.colocrossing.com
172.245.49.180	PTR	172-245-49-180-host.colocrossing.com
172.245.49.192	PTR	172-245-49-192-host.colocrossing.com
172.245.49.194	PTR	172-245-49-194-host.colocrossing.com
172.245.49.197	PTR	172-245-49-197-host.colocrossing.com
172.245.49.200	PTR	172-245-49-200-host.colocrossing.com
172.245.49.209	A	dollarincentive.com
172.245.49.210	PTR	172-245-49-210-host.colocrossing.com
172.245.49.210	A	res.dollarincentive.com
172.245.49.254	A	nac.insureurlife.com
172.245.50.49	PTR	172-245-50-49-host.colocrossing.com
172.245.50.93	PTR	172-245-50-93-host.colocrossing.com
172.245.50.118	PTR	172-245-50-118-host.colocrossing.com
172.245.50.143	PTR	172-245-50-143-host.colocrossing.com
172.245.50.176	PTR	172-245-50-176-host.colocrossing.com
172.245.50.210	PTR	172-245-50-210-host.colocrossing.com
172.245.50.228	PTR	172-245-50-228-host.colocrossing.com
172.245.51.15	PTR	172-245-51-15-host.colocrossing.com
172.245.51.33	PTR	172-245-51-33-host.colocrossing.com
172.245.51.73	PTR	172-245-51-73-host.colocrossing.com
172.245.51.134	PTR	172-245-51-134-host.colocrossing.com
172.245.51.140	PTR	172-245-51-140-host.colocrossing.com
172.245.51.166	PTR	172-245-51-166-host.colocrossing.com
172.245.51.207	PTR	172-245-51-207-host.colocrossing.com
172.245.51.232	PTR	172-245-51-232-host.colocrossing.com
172.245.51.248	PTR	172-245-51-248-host.colocrossing.com