Robtex

Up: 173.28.0.0/20
Can't show all results, try to descend to a more specific CIDR
Down left: 173.28.8.0/22
Down right: 173.28.12.0/22
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
173.28.8.0	A+PTR	173-28-8-0.client.mchsi.com
173.28.8.1	PTR	173-28-8-1.client.mchsi.com
173.28.8.80	A+PTR	173-28-8-80.client.mchsi.com
173.28.9.2	A	173-28-9-2.client.mchsi.com
173.28.10.28	A+PTR	173-28-10-28.client.mchsi.com
173.28.10.28	A	mljallen.com
173.28.10.46	A	173-28-10-46.client.mchsi.com
173.28.10.104	A+PTR	173-28-10-104.client.mchsi.com
173.28.11.24	A+PTR	173-28-11-24.client.mchsi.com
173.28.11.24	A	theycallmedotcom.com
173.28.11.91	A+PTR	173-28-11-91.client.mchsi.com
173.28.11.219	PTR	173-28-11-219.client.mchsi.com
173.28.12.117	A	jsehome.us
173.28.12.117	A	jsehome.net
173.28.12.117	A	mail.jsehome.net
173.28.12.173	A	mx.opentheismboard.org
173.28.12.173	A	mail.opentheismboard.org
173.28.12.176	A+PTR	173-28-12-176.client.mchsi.com
173.28.12.177	PTR	173-28-12-177.client.mchsi.com
173.28.12.251	A+PTR	173-28-12-251.client.mchsi.com
173.28.12.251	A	typhoonsolutions.com
173.28.13.91	A+PTR	173-28-13-91.client.mchsi.com
173.28.13.100	A+PTR	173-28-13-100.client.mchsi.com
173.28.13.125	A+PTR	173-28-13-125.client.mchsi.com
173.28.13.125	A	newinteriorsdesign.com
173.28.13.125	A	tmarksigns.com
173.28.13.193	A	toastyduck.com
173.28.13.215	A+PTR	173-28-13-215.client.mchsi.com
173.28.13.215	A	ghosthacker.com
173.28.14.12	A	mail.slipsec.org
173.28.14.41	A+PTR	173-28-14-41.client.mchsi.com
173.28.14.83	A+PTR	173-28-14-83.client.mchsi.com
173.28.14.91	A+PTR	173-28-14-91.client.mchsi.com
173.28.14.223	A+PTR	173-28-14-223.client.mchsi.com
173.28.14.223	A	dc2.viensfamily.net
173.28.14.223	A	viensfamily.net
173.28.14.234	A+PTR	173-28-14-234.client.mchsi.com
173.28.14.234	A	coreyford.homedns.org
173.28.15.2	A+PTR	173-28-15-2.client.mchsi.com
173.28.15.4	A	173-28-15-4.client.mchsi.com
173.28.15.7	A	173-28-15-7.client.mchsi.com
173.28.15.10	A+PTR	173-28-15-10.client.mchsi.com
173.28.15.12	A	173-28-15-12.client.mchsi.com
173.28.15.17	PTR	173-28-15-17.client.mchsi.com
173.28.15.18	A+PTR	173-28-15-18.client.mchsi.com
173.28.15.23	A	173-28-15-23.client.mchsi.com
173.28.15.27	PTR	173-28-15-27.client.mchsi.com
173.28.15.31	A	173-28-15-31.client.mchsi.com
173.28.15.34	A	173-28-15-34.client.mchsi.com
173.28.15.36	A	173-28-15-36.client.mchsi.com
173.28.15.42	A+PTR	173-28-15-42.client.mchsi.com
173.28.15.46	A	173-28-15-46.client.mchsi.com
173.28.15.48	PTR	173-28-15-48.client.mchsi.com
173.28.15.51	PTR	173-28-15-51.client.mchsi.com
173.28.15.56	A	173-28-15-56.client.mchsi.com
173.28.15.61	A	173-28-15-61.client.mchsi.com
173.28.15.74	A+PTR	173-28-15-74.client.mchsi.com
173.28.15.80	A+PTR	173-28-15-80.client.mchsi.com
173.28.15.81	A+PTR	173-28-15-81.client.mchsi.com
173.28.15.85	A	173-28-15-85.client.mchsi.com
173.28.15.89	A+PTR	173-28-15-89.client.mchsi.com
173.28.15.91	A+PTR	173-28-15-91.client.mchsi.com
173.28.15.95	A	173-28-15-95.client.mchsi.com
173.28.15.107	A+PTR	173-28-15-107.client.mchsi.com
173.28.15.118	A	173-28-15-118.client.mchsi.com
173.28.15.119	A	173-28-15-119.client.mchsi.com
173.28.15.127	A	173-28-15-127.client.mchsi.com
173.28.15.138	A	173-28-15-138.client.mchsi.com
173.28.15.166	A	173-28-15-166.client.mchsi.com
173.28.15.168	A+PTR	173-28-15-168.client.mchsi.com
173.28.15.172	A	173-28-15-172.client.mchsi.com
173.28.15.182	A	173-28-15-182.client.mchsi.com
173.28.15.184	A	173-28-15-184.client.mchsi.com
173.28.15.185	A	kathan.us
173.28.15.187	A+PTR	173-28-15-187.client.mchsi.com
173.28.15.193	A+PTR	173-28-15-193.client.mchsi.com
173.28.15.194	A	173-28-15-194.client.mchsi.com
173.28.15.195	PTR	173-28-15-195.client.mchsi.com
173.28.15.196	A	173-28-15-196.client.mchsi.com
173.28.15.201	A+PTR	173-28-15-201.client.mchsi.com
173.28.15.217	A+PTR	173-28-15-217.client.mchsi.com
173.28.15.226	PTR	173-28-15-226.client.mchsi.com
173.28.15.228	A	173-28-15-228.client.mchsi.com
173.28.15.230	A	173-28-15-230.client.mchsi.com
173.28.15.238	A	173-28-15-238.client.mchsi.com
173.28.15.242	A	173-28-15-242.client.mchsi.com
173.28.15.247	A	173-28-15-247.client.mchsi.com
173.28.15.248	A+PTR	173-28-15-248.client.mchsi.com