Robtex

Up: 177.91.160.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 177.91.160.0/23
Down right: 177.91.162.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
177.91.160.0	PTR	ox-spo1-core0-ip.openx.com.br
177.91.160.66	A+PTR	jack.openx.com.br
177.91.160.66	A	pop.stratus.com.br
177.91.160.91	A+PTR	sawyer.openx.com.br
177.91.160.91	A	ashafilmes.com.br
177.91.160.91	A	openx.com.br
177.91.160.92	A	bernard.openx.com.br
177.91.160.97	PTR	ethan.openx.com.br
177.91.160.97	A	goodwin.openx.com.br
177.91.160.98	PTR	goodwin.openx.com.br
177.91.160.98	A	ethan.openx.com.br
177.91.160.99	A+PTR	locke.openx.com.br
177.91.160.100	A+PTR	hurley.openx.com.br
177.91.160.140	PTR	cache.google.com
177.91.160.140	A	r1---sn-v2xom-bg0e.googlevideo.com
177.91.160.140	A	r1.sn-v2xom-bg0e.googlevideo.com
177.91.160.141	PTR	cache.google.com
177.91.160.141	A	r2.sn-v2xom-bg0e.gvt1.com
177.91.160.142	PTR	cache.google.com
177.91.160.143	PTR	cache.google.com
177.91.160.230	A+PTR	a177-91-160-230.deploy.akamaitechnologies.com
177.91.160.230	A	n0dsw3.akamai.net
177.91.160.230	A	n1ntt1.akamai.net
177.91.160.245	A+PTR	177-91-160-245.openx.com.br
177.91.160.245	A	ipv4-c001-cgh002-openx-isp.1.oca.nflxvideo.net
177.91.162.140	A+PTR	177-91-162-140.openx.com.br
177.91.162.140	A	r1.sn-v2xom-bg0l.googlevideo.com
177.91.162.140	A	r1.sn-v2xom-bg0l.gvt1.com
177.91.162.141	PTR	177-91-162-141.openx.com.br
177.91.162.141	A	r2.sn-v2xom-bg0l.c.android.clients.google.com
177.91.162.161	A+PTR	177-91-162-161.openx.com.br
177.91.162.161	A	ipv4-c001-cgh001-openx-isp.1.oca.nflxvideo.net
177.91.163.255	PTR	177-91-163-255.openx.com.br