Robtex

Up: 173.16.48.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 173.16.52.0/23
Down right: 173.16.54.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
173.16.52.16	PTR	173-16-52-16.client.mchsi.com
173.16.52.16	A	parker.ws
173.16.52.16	A	psmith-home.dyndns.org
173.16.52.85	PTR	173-16-52-85.client.mchsi.com
173.16.52.85	A	alabamaiorg.com
173.16.52.85	A	usairwaysva.org
173.16.52.215	A	earth.productions
173.16.53.2	A+PTR	173-16-53-2.client.mchsi.com
173.16.53.4	A+PTR	173-16-53-4.client.mchsi.com
173.16.53.5	A+PTR	173-16-53-5.client.mchsi.com
173.16.53.9	A+PTR	173-16-53-9.client.mchsi.com
173.16.53.13	A+PTR	173-16-53-13.client.mchsi.com
173.16.53.15	A+PTR	173-16-53-15.client.mchsi.com
173.16.53.23	A+PTR	173-16-53-23.client.mchsi.com
173.16.53.25	A+PTR	173-16-53-25.client.mchsi.com
173.16.53.28	A+PTR	173-16-53-28.client.mchsi.com
173.16.53.30	A+PTR	173-16-53-30.client.mchsi.com
173.16.53.50	A+PTR	173-16-53-50.client.mchsi.com
173.16.53.54	A+PTR	173-16-53-54.client.mchsi.com
173.16.53.55	A+PTR	173-16-53-55.client.mchsi.com
173.16.53.57	A+PTR	173-16-53-57.client.mchsi.com
173.16.53.59	A+PTR	173-16-53-59.client.mchsi.com
173.16.53.61	A+PTR	173-16-53-61.client.mchsi.com
173.16.53.64	A+PTR	173-16-53-64.client.mchsi.com
173.16.53.67	A+PTR	173-16-53-67.client.mchsi.com
173.16.53.68	A+PTR	173-16-53-68.client.mchsi.com
173.16.53.69	A+PTR	173-16-53-69.client.mchsi.com
173.16.53.70	A+PTR	173-16-53-70.client.mchsi.com
173.16.53.72	A+PTR	173-16-53-72.client.mchsi.com
173.16.53.76	A+PTR	173-16-53-76.client.mchsi.com
173.16.53.78	A+PTR	173-16-53-78.client.mchsi.com
173.16.53.80	A+PTR	173-16-53-80.client.mchsi.com
173.16.53.84	A+PTR	173-16-53-84.client.mchsi.com
173.16.53.87	A	173-16-53-87.client.mchsi.com
173.16.53.89	A+PTR	173-16-53-89.client.mchsi.com
173.16.53.97	A+PTR	173-16-53-97.client.mchsi.com
173.16.53.99	A+PTR	173-16-53-99.client.mchsi.com
173.16.53.107	A+PTR	173-16-53-107.client.mchsi.com
173.16.53.115	A+PTR	173-16-53-115.client.mchsi.com
173.16.53.119	A+PTR	173-16-53-119.client.mchsi.com
173.16.53.127	A+PTR	173-16-53-127.client.mchsi.com
173.16.53.131	A+PTR	173-16-53-131.client.mchsi.com
173.16.53.141	A+PTR	173-16-53-141.client.mchsi.com
173.16.53.142	A+PTR	173-16-53-142.client.mchsi.com
173.16.53.146	A+PTR	173-16-53-146.client.mchsi.com
173.16.53.160	A+PTR	173-16-53-160.client.mchsi.com
173.16.53.164	A+PTR	173-16-53-164.client.mchsi.com
173.16.53.165	A+PTR	173-16-53-165.client.mchsi.com
173.16.53.166	A+PTR	173-16-53-166.client.mchsi.com
173.16.53.167	PTR	173-16-53-167.client.mchsi.com
173.16.53.170	A+PTR	173-16-53-170.client.mchsi.com
173.16.53.183	A+PTR	173-16-53-183.client.mchsi.com
173.16.53.185	A+PTR	173-16-53-185.client.mchsi.com
173.16.53.189	PTR	173-16-53-189.client.mchsi.com
173.16.53.189	A	mail.fulks.org
173.16.53.189	A	www.fulks.org
173.16.53.196	A+PTR	173-16-53-196.client.mchsi.com
173.16.53.206	A+PTR	173-16-53-206.client.mchsi.com
173.16.53.207	A+PTR	173-16-53-207.client.mchsi.com
173.16.53.209	A+PTR	173-16-53-209.client.mchsi.com
173.16.53.214	A+PTR	173-16-53-214.client.mchsi.com
173.16.53.218	A+PTR	173-16-53-218.client.mchsi.com
173.16.53.225	A+PTR	173-16-53-225.client.mchsi.com
173.16.53.232	A+PTR	173-16-53-232.client.mchsi.com
173.16.53.234	PTR	173-16-53-234.client.mchsi.com
173.16.53.245	A+PTR	173-16-53-245.client.mchsi.com
173.16.53.246	A+PTR	173-16-53-246.client.mchsi.com
173.16.53.248	A+PTR	173-16-53-248.client.mchsi.com
173.16.53.254	A+PTR	173-16-53-254.client.mchsi.com
173.16.54.1	A	173-16-54-1.client.mchsi.com
173.16.54.42	A	greptar.dyndns.org
173.16.54.116	A+PTR	173-16-54-116.client.mchsi.com
173.16.54.173	A	173-16-54-173.client.mchsi.com
173.16.54.226	PTR	173-16-54-226.client.mchsi.com
173.16.54.226	A	cartruckclubs.com
173.16.54.226	A	mail.tazib.com
173.16.54.255	A	apits.us
173.16.55.4	A+PTR	173-16-55-4.client.mchsi.com
173.16.55.58	A	173-16-55-58.client.mchsi.com
173.16.55.113	A+PTR	173-16-55-113.client.mchsi.com
173.16.55.201	A+PTR	173-16-55-201.client.mchsi.com
173.16.55.201	A	cdwyland.net
173.16.55.201	A	cdwyland.com