Robtex

Up: 168.181.232.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 168.181.236.0/23
Down right: 168.181.238.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
168.181.236.3	A+PTR	dns1.infoartestelecom.com.br
168.181.236.3	A	infoartestelecom.com.br
168.181.236.3	A	pop.infoartestelecom.com.br
168.181.236.4	PTR	4-236-181-168.infoartestelecom.com.br
168.181.236.4	A	ns2.infoartestelecom.com.br
168.181.236.5	A+PTR	dns2.infoartestelecom.com.br
168.181.236.6	PTR	velocidade2.infoartestelecom.com.br
168.181.239.10	A+PTR	10-239-181-168.infoartestelecom.com.br
168.181.239.190	A+PTR	168-181-239-190.dynamic.infoartestelecom.com.br