Robtex

Up: 191.6.144.0/20
Can't show all results, try to descend to a more specific CIDR
Down left: 191.6.152.0/22
Down right: 191.6.156.0/22
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
191.6.152.3	PTR	server.sicalnet.com.br
191.6.152.3	A	silker.com.br
191.6.152.3	A	chapadafest.com.br
191.6.152.4	PTR	ns1.sicalnet.com.br
191.6.152.6	PTR	ns2.sicalnet.com.br
191.6.155.152	A	www.se.sebrae.com.br