Robtex

Up: 209.42.56.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 209.42.56.0/23
Down right: 209.42.58.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
209.42.56.111	A+PTR	static.user111.209.42.56.dsli.com
209.42.56.120	A	office.tripsrusinc.com
209.42.56.136	A+PTR	static.user136.209.42.56.dsli.com
209.42.56.140	A+PTR	static.user140.209.42.56.dsli.com
209.42.56.147	PTR	host-209-42-56-147.reverse.opticaltel.com
209.42.56.147	A	static.user147.209.42.56.dsli.com
209.42.56.150	PTR	host-209-42-56-150.reverse.opticaltel.com
209.42.56.150	A	static.user150.209.42.56.dsli.com
209.42.56.152	PTR	host-209-42-56-152.reverse.opticaltel.com
209.42.56.152	A	static.user152.209.42.56.dsli.com
209.42.56.153	A+PTR	static.user153.209.42.56.dsli.com
209.42.56.168	A+PTR	static.user168.209.42.56.dsli.com
209.42.56.180	A+PTR	static.user180.209.42.56.dsli.com
209.42.56.185	A+PTR	static.user185.209.42.56.dsli.com
209.42.56.189	A+PTR	static.user189.209.42.56.dsli.com
209.42.56.191	A+PTR	static.user191.209.42.56.dsli.com
209.42.56.194	A+PTR	static.user194.209.42.56.dsli.com
209.42.56.195	A+PTR	static.user195.209.42.56.dsli.com
209.42.56.197	A+PTR	static.user197.209.42.56.dsli.com
209.42.56.218	A+PTR	static.user218.209.42.56.dsli.com
209.42.56.221	A+PTR	static.user221.209.42.56.dsli.com
209.42.56.222	A+PTR	static.user222.209.42.56.dsli.com
209.42.56.233	A+PTR	static.user233.209.42.56.dsli.com
209.42.56.244	A+PTR	static.user244.209.42.56.dsli.com
209.42.57.1	PTR	ds3.57-1-gr.mia.fl
209.42.57.20	PTR	host-209-42-57-20.reverse.opticaltel.com
209.42.57.20	A	static.user20.209.42.57.dsli.com
209.42.57.35	A	remote.integritasmiami.com
209.42.57.35	A	mail.integritasmiami.com
209.42.57.35	A	mail2.integritasmiami.com
209.42.57.50	PTR	static.user50.209.42.57.dsli.com
209.42.57.66	PTR	static.user66.209.42.57.dsli.com
209.42.57.114	A	mail.meiequipmentservices.com
209.42.57.114	A	mail.meihealthcaregroup.com
209.42.57.114	A	mail.meifoundation.org
209.42.57.116	PTR	host-209-42-57-116.reverse.opticaltel.com
209.42.57.116	A	mail.meiwomenshealthcare.com
209.42.57.128	PTR	host-209-42-57-128.reverse.opticaltel.com
209.42.57.130	A	mail.velolux.net
209.42.57.141	PTR	static.user141.209.42.57.dsli.com
209.42.57.145	A+PTR	static.user145.209.42.57.dsli.com
209.42.57.145	A	mail.velolux.com
209.42.57.157	PTR	static.user157.209.42.57.dsli.com
209.42.57.158	PTR	static.user158.209.42.57.dsli.com
209.42.57.159	PTR	host-209-42-57-159.reverse.opticaltel.com
209.42.57.159	A	ibmprofessionalservices.com
209.42.57.162	PTR	static.user162.209.42.57.dsli.com
209.42.57.163	PTR	static.user163.209.42.57.dsli.com
209.42.57.163	A	sapprofessionalservices.com
209.42.57.165	PTR	static.user165.209.42.57.dsli.com
209.42.57.165	A	teradataprofessionalservices.com
209.42.57.166	A+PTR	static.user166.209.42.57.dsli.com
209.42.57.167	A+PTR	static.user167.209.42.57.dsli.com
209.42.57.167	A	cognosprofessionalservices.com
209.42.57.170	A+PTR	static.user170.209.42.57.dsli.com
209.42.57.170	PTR	exchange.thekessmans.com
209.42.57.170	PTR	yourmisdepartment.com
209.42.57.172	A	comoyocomo.com
209.42.58.1	PTR	ds3.58-1-gr.mia.fl
209.42.58.3	PTR	static.user3.209.42.58.dsli.com
209.42.58.5	A+PTR	static.user5.209.42.58.dsli.com
209.42.58.11	PTR	static.user11.209.42.58.dsli.com
209.42.58.14	A+PTR	static.user14.209.42.58.dsli.com
209.42.58.19	A+PTR	static.user19.209.42.58.dsli.com
209.42.58.24	A+PTR	static.user24.209.42.58.dsli.com
209.42.58.25	A+PTR	static.user25.209.42.58.dsli.com
209.42.58.29	A+PTR	static.user29.209.42.58.dsli.com
209.42.58.32	A	static.user32.209.42.58.dsli.com
209.42.58.43	A+PTR	static.user43.209.42.58.dsli.com
209.42.58.44	A+PTR	static.user44.209.42.58.dsli.com
209.42.58.54	PTR	static.user32.209.42.58.dsli.com
209.42.58.54	PTR	static.user52.209.42.58.dsli.com
209.42.58.54	PTR	static.user54.209.42.58.dsli.com
209.42.58.57	A+PTR	static.user57.209.42.58.dsli.com
209.42.58.60	A+PTR	static.user60.209.42.58.dsli.com
209.42.58.61	A+PTR	static.user61.209.42.58.dsli.com
209.42.58.62	A+PTR	static.user62.209.42.58.dsli.com
209.42.58.64	PTR	static.user64.209.42.58.dsli.com
209.42.58.66	A+PTR	static.user66.209.42.58.dsli.com
209.42.58.67	A+PTR	static.user67.209.42.58.dsli.com
209.42.58.68	A+PTR	static.user68.209.42.58.dsli.com
209.42.58.71	A+PTR	static.user71.209.42.58.dsli.com
209.42.58.76	PTR	static.user76.209.42.58.dsli.com
209.42.58.81	PTR	static.user81.209.42.58.dsli.com
209.42.58.82	PTR	static.user82.209.42.58.dsli.com
209.42.58.87	A+PTR	static.user87.209.42.58.dsli.com
209.42.58.89	A+PTR	static.user89.209.42.58.dsli.com
209.42.58.94	A+PTR	static.user94.209.42.58.dsli.com
209.42.58.95	A+PTR	static.user95.209.42.58.dsli.com
209.42.58.96	A+PTR	static.user96.209.42.58.dsli.com
209.42.58.98	A+PTR	static.user98.209.42.58.dsli.com
209.42.58.99	PTR	static.user99.209.42.58.dsli.com
209.42.58.101	A+PTR	static.user101.209.42.58.dsli.com
209.42.58.110	PTR	mail.uneedus.com
209.42.58.112	PTR	static.user112.209.42.58.dsli.com
209.42.58.114	A+PTR	static.user114.209.42.58.dsli.com
209.42.58.117	A+PTR	static.user117.209.42.58.dsli.com
209.42.58.120	A+PTR	static.user120.209.42.58.dsli.com
209.42.58.127	PTR	static.user127.209.42.58.dsli.com
209.42.58.130	A+PTR	static.user130.209.42.58.dsli.com
209.42.58.131	A+PTR	static.user131.209.42.58.dsli.com
209.42.58.135	A+PTR	static.user135.209.42.58.dsli.com
209.42.58.138	A+PTR	static.user138.209.42.58.dsli.com
209.42.58.145	A+PTR	static.user145.209.42.58.dsli.com
209.42.58.149	A+PTR	static.user149.209.42.58.dsli.com
209.42.58.150	PTR	static.user150.209.42.58.dsli.com
209.42.58.153	A+PTR	static.user153.209.42.58.dsli.com
209.42.58.159	A+PTR	static.user159.209.42.58.dsli.com
209.42.58.164	PTR	owa.coastalsystemsint.com
209.42.58.167	A+PTR	static.user167.209.42.58.dsli.com
209.42.58.170	PTR	static.user170.209.42.58.dsli.com
209.42.58.172	A+PTR	static.user172.209.42.58.dsli.com
209.42.58.174	A+PTR	static.user174.209.42.58.dsli.com
209.42.58.176	A+PTR	static.user176.209.42.58.dsli.com
209.42.58.178	A+PTR	static.user178.209.42.58.dsli.com
209.42.58.181	A+PTR	static.user181.209.42.58.dsli.com
209.42.58.183	A+PTR	static.user183.209.42.58.dsli.com
209.42.58.186	PTR	static.user186.209.42.58.dsli.com
209.42.58.188	A+PTR	static.user188.209.42.58.dsli.com
209.42.58.194	A+PTR	static.user194.209.42.58.dsli.com
209.42.58.195	PTR	static.user195.209.42.58.dsli.com
209.42.58.201	A+PTR	static.user201.209.42.58.dsli.com
209.42.58.202	A+PTR	static.user202.209.42.58.dsli.com
209.42.58.203	A+PTR	static.user203.209.42.58.dsli.com
209.42.58.207	A+PTR	static.user207.209.42.58.dsli.com
209.42.58.210	A+PTR	static.user210.209.42.58.dsli.com
209.42.58.212	A+PTR	static.user212.209.42.58.dsli.com
209.42.58.217	A+PTR	static.user217.209.42.58.dsli.com
209.42.58.223	A+PTR	static.user223.209.42.58.dsli.com
209.42.58.224	PTR	static.user224.209.42.58.dsli.com
209.42.58.228	A+PTR	static.user228.209.42.58.dsli.com
209.42.58.229	PTR	static.user229.209.42.58.dsli.com
209.42.58.231	A+PTR	static.user231.209.42.58.dsli.com
209.42.58.232	A+PTR	static.user232.209.42.58.dsli.com
209.42.58.237	PTR	static.user237.209.42.58.dsli.com
209.42.58.246	A+PTR	static.user246.209.42.58.dsli.com
209.42.58.248	A+PTR	static.user248.209.42.58.dsli.com
209.42.58.249	A+PTR	static.user249.209.42.58.dsli.com
209.42.58.254	A+PTR	static.user254.209.42.58.dsli.com
209.42.59.23	A	goldengladesnursing.com
209.42.59.27	A	zmail.cardiacall.com
209.42.59.28	A	teamhealthcaregroup.com
209.42.59.86	A+PTR	static.user86.209.42.59.dsli.com
209.42.59.195	A	micaelprojectmanagement.com