Robtex

Up: 198.147.16.0/21
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Down left: 198.147.16.0/23
Down right: 198.147.18.0/23

IP	Type	Hostname
198.147.16.0	PTR	198147016000.discovery.com
198.147.16.9	A+PTR	auth04.ns.discovery.com
198.147.16.9	A	auth.ns.discovery.com
198.147.16.101	PTR	198147016101.discovery.com
198.147.16.112	PTR	198147016112.discovery.com
198.147.16.139	PTR	198147016139.discovery.com
198.147.17.0	PTR	198147017000.discovery.com
198.147.17.5	PTR	198147017005.discovery.com
198.147.17.66	PTR	198147017066.discovery.com
198.147.19.0	PTR	198147019000.discovery.com
198.147.19.2	PTR	198147019002.discovery.com
198.147.19.39	PTR	198147019039.discovery.com
198.147.19.41	PTR	198147019041.discovery.com
198.147.19.42	PTR	198147019042.discovery.com
198.147.19.70	PTR	198147019070.discovery.com
198.147.19.70	A	email.discovery.com