Robtex

Up: 177.21.0.0/19
Can't show all results, try to descend to a more specific CIDR
Down left: 177.21.16.0/21
Down right: 177.21.24.0/21
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
177.21.17.49	PTR	49.17.21.177.teletalk.net.br
177.21.17.83	PTR	177-21-17-83.host.teletalk.net.br
177.21.19.163	PTR	177-21-19-163.host.teletalk.net.br
177.21.20.49	PTR	49.20.21.177.teletalk.net.br
177.21.21.2	PTR	2.21.21.177.teletalk.net.br
177.21.21.19	PTR	19.21.21.177.teletalk.net.br
177.21.22.211	PTR	211.22.21.177.teletalk.net.br
177.21.24.83	PTR	83.24.21.177.teletalk.net.br
177.21.24.162	PTR	162.24.21.177.teletalk.net.br
177.21.26.198	A	postosuniao.com.br
177.21.26.224	PTR	224.26.21.177.teletalk.net.br
177.21.27.66	PTR	66.27.21.177.teletalk.net.br
177.21.27.66	A	vpn.saosalvador.edu.br
177.21.28.67	PTR	67.28.21.177.teletalk.net.br
177.21.28.86	A	mail2.bravocm.com.br
177.21.30.91	A	icatubrasil.com.br
177.21.30.91	A	www.icatubrasil.com.br
177.21.30.91	A	www.icatubahia.com.br
177.21.30.147	PTR	147.30.21.177.teletalk.net.br
177.21.30.224	PTR	224.30.21.177.teletalk.net.br
177.21.31.67	PTR	67.31.21.177.teletalk.net.br