Robtex

Up: 54.231.230.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 54.231.230.0/25
Down right: 54.231.230.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
54.231.230.0	PTR	s3-website-ap-northeast-1.amazonaws.com
54.231.230.0	A	tokyo-kazoku.jp
54.231.230.0	A	www.theoria.ne.jp.s3-website-ap-northeast-1.amazonaws.com
54.231.230.1	PTR	s3-ap-northeast-1-w.amazonaws.com
54.231.230.4	PTR	s3-website-ap-northeast-1.amazonaws.com
54.231.230.4	A	www.theoria.ne.jp.s3-website-ap-northeast-1.amazonaws.com
54.231.230.4	A	seraphyware.net
54.231.230.5	PTR	s3-ap-northeast-1-w.amazonaws.com
54.231.230.5	A	00002.s3.amazonaws.com
54.231.230.8	PTR	s3-website-ap-northeast-1.amazonaws.com
54.231.230.8	A	pr.kenko.com
54.231.230.8	A	codexr.info
54.231.230.9	PTR	s3-ap-northeast-1-w.amazonaws.com
54.231.230.9	A	00002.s3.amazonaws.com
54.231.230.11	PTR	s3-ap-northeast-1-r-w.amazonaws.com
54.231.230.12	PTR	s3-website-ap-northeast-1.amazonaws.com
54.231.230.12	A	www.theoria.ne.jp.s3-website-ap-northeast-1.amazonaws.com
54.231.230.12	A	codexr.info
54.231.230.13	A	cd-ladsp-com.s3.amazonaws.com
54.231.230.15	A	p1.off.travel
54.231.230.16	PTR	s3-website-ap-northeast-1.amazonaws.com
54.231.230.16	A	www.theoria.ne.jp.s3-website-ap-northeast-1.amazonaws.com
54.231.230.16	A	xn--vuqt16bqncmrqt7go0rx1nytar29f.net
54.231.230.17	PTR	s3-ap-northeast-1-w.amazonaws.com
54.231.230.18	PTR	s3-ap-northeast-1.amazonaws.com
54.231.230.20	PTR	s3-website-ap-northeast-1.amazonaws.com
54.231.230.20	A	tokyo-kazoku.jp
54.231.230.20	A	www.theoria.ne.jp.s3-website-ap-northeast-1.amazonaws.com
54.231.230.21	A	s3-w-a.ap-northeast-1.amazonaws.com
54.231.230.21	A	ap-jpn-00001.s3.amazonaws.com
54.231.230.23	PTR	s3-ap-northeast-1-r-w.amazonaws.com
54.231.230.23	A	p1.off.travel