Robtex

Up: 177.21.24.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 177.21.28.0/23
Down right: 177.21.30.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
177.21.28.67	PTR	67.28.21.177.teletalk.net.br
177.21.28.77	PTR	77.28.21.177.teletalk.net.br
177.21.28.84	PTR	84.28.21.177.teletalk.net.br
177.21.28.86	PTR	177-21-28-86.host.teletalk.net.br
177.21.28.86	A	mail2.bravocm.com.br
177.21.28.154	PTR	154.28.21.177.teletalk.net.br
177.21.29.5	PTR	5.29.21.177.teletalk.net.br
177.21.29.86	PTR	86.29.21.177.teletalk.net.br
177.21.29.157	PTR	157.29.21.177.teletalk.net.br
177.21.29.158	PTR	177-21-29-158.host.teletalk.net.br
177.21.29.167	PTR	167.29.21.177.teletalk.net.br
177.21.29.204	PTR	204.29.21.177.teletalk.net.br
177.21.29.236	PTR	236.29.21.177.teletalk.net.br
177.21.30.37	PTR	37.30.21.177.teletalk.net.br
177.21.30.38	PTR	177-21-30-38.host.teletalk.net.br
177.21.30.91	PTR	91.30.21.177.teletalk.net.br
177.21.30.91	A	icatubrasil.com.br
177.21.30.91	A	www.icatubrasil.com.br
177.21.30.92	PTR	177-21-30-92.host.teletalk.net.br
177.21.30.92	A	cidaderevista.com.br
177.21.30.92	A	condominiosweb.com.br
177.21.30.94	PTR	177-21-30-94.host.teletalk.net.br
177.21.30.147	PTR	147.30.21.177.teletalk.net.br
177.21.30.171	PTR	171.30.21.177.teletalk.net.br
177.21.30.180	PTR	180.30.21.177.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
177.21.31.206	PTR	206.31.21.177.teletalk.net.br