Robtex

Up: 192.3.56.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 192.3.56.0/23
Down right: 192.3.58.0/23

IP	Type	Hostname
192.3.56.20	PTR
192.3.56.38	PTR
192.3.56.66	PTR
192.3.56.80	PTR
192.3.56.89	PTR
192.3.56.100	PTR
192.3.56.196	PTR
192.3.57.253	PTR
192.3.58.8	PTR
192.3.58.18	PTR
192.3.58.20	PTR
192.3.58.50	PTR
192.3.58.52	PTR
192.3.58.60	PTR
192.3.58.64	PTR
192.3.58.96	PTR
192.3.58.125	PTR
192.3.59.103	PTR
192.3.59.144	PTR	192-3-59-144-host.colocrossing.com
192.3.59.144	A	darkorbit.oyun.bursa-buku-online.com
192.3.59.145	PTR
192.3.59.148	PTR
192.3.59.152	A	vastgoedtransparant.com
192.3.59.159	PTR
192.3.59.160	PTR
192.3.59.185	PTR
192.3.59.186	PTR	192-3-59-186-host.colocrossing.com
192.3.59.186	A	loona.cn
192.3.59.186	A	acgdomains.com
192.3.59.187	A	mgonetwork.com
192.3.59.188	PTR	192-3-59-188-host.colocrossing.com
192.3.59.188	A	greensenegal.net
192.3.59.189	PTR
192.3.59.191	PTR
192.3.59.197	A	peacenowconversation.org
192.3.59.199	PTR
192.3.59.200	PTR	192-3-59-200-host.colocrossing.com
192.3.59.200	A	marc-jacobsonsale.com
192.3.59.204	PTR
192.3.59.211	PTR	192-3-59-211-host.colocrossing.com
192.3.59.211	A	paybills-businessmail00.com
192.3.59.217	PTR
192.3.59.222	A	spapowered.com
192.3.59.226	PTR
192.3.59.238	PTR
192.3.59.245	PTR
192.3.59.247	PTR