Robtex

Up: 123.31.32.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 123.31.32.0/23
Down right: 123.31.34.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
123.31.32.5	PTR	localhost
123.31.32.7	PTR	localhost
123.31.32.9	PTR	localhost
123.31.32.30	PTR	localhost
123.31.32.38	PTR	static.vnpt.vn
123.31.32.44	PTR	localhost
123.31.32.44	A	yenbai.gov.vn
123.31.32.68	PTR	static.vnpt.vn
123.31.32.70	PTR	localhost
123.31.32.101	PTR	static.vnpt.vn
123.31.32.130	A	daily.vnshop.vn
123.31.32.134	A	admin-hddt2019.phongvu.vn
123.31.32.144	PTR	static.vnpt.vn
123.31.32.144	A	wifi.phongvu.vn
123.31.32.150	PTR	static.vnpt.vn
123.31.32.150	A	dev-tracking.teko.vn
123.31.32.162	A	gcafe.teko.vn
123.31.32.164	PTR	static.vnpt.vn
123.31.32.164	A	analytics.teko.vn
123.31.32.170	PTR	localhost
123.31.32.170	A	phongvu.vn
123.31.32.170	A	img1-cdn.phongvu.vn
123.31.32.194	A	file.services.teko.vn
123.31.32.206	A	congdong.phongvu.vn
123.31.32.208	A	crm.phongvu.vn
123.31.32.219	A	api-wms.phongvu.vn
123.31.33.13	PTR	localhost
123.31.33.13	A	www.benhvienyhct-phcnkhanhhoa.com.vn
123.31.33.13	A	achaufood.com.vn
123.31.33.60	PTR	localhost
123.31.34.1	PTR	localhost
123.31.34.15	PTR	localhost
123.31.34.16	PTR	localhost
123.31.34.17	PTR	localhost
123.31.34.18	PTR	localhost
123.31.34.31	PTR	static.vnpt.vn
123.31.34.39	PTR	localhost
123.31.34.41	PTR	localhost
123.31.34.44	PTR	localhost
123.31.34.47	PTR	localhost
123.31.34.52	PTR	localhost
123.31.34.73	PTR	localhost
123.31.34.74	PTR	localhost
123.31.34.75	PTR	localhost
123.31.34.92	PTR	localhost
123.31.34.94	PTR	static.vnpt.vn
123.31.34.95	PTR	localhost
123.31.34.100	PTR	localhost
123.31.34.109	PTR	localhost
123.31.34.121	PTR	localhost
123.31.34.136	PTR	localhost
123.31.34.143	PTR	localhost
123.31.34.144	PTR	localhost
123.31.34.144	A	tlsoft.info
123.31.34.149	PTR	localhost
123.31.34.170	PTR	localhost
123.31.34.172	PTR	localhost
123.31.34.179	PTR	localhost
123.31.34.180	PTR	localhost
123.31.34.182	PTR	localhost
123.31.34.182	A	samprp.net
123.31.34.186	PTR	localhost
123.31.34.192	PTR	localhost
123.31.34.201	PTR	localhost
123.31.34.213	PTR	localhost
123.31.34.214	PTR	localhost
123.31.34.215	PTR	localhost
123.31.34.216	PTR	localhost
123.31.34.218	PTR	localhost
123.31.34.219	PTR	localhost
123.31.34.220	PTR	localhost
123.31.34.221	PTR	localhost
123.31.34.222	PTR	localhost
123.31.34.223	PTR	localhost
123.31.34.236	A	thdmediaglobal.com
123.31.34.238	PTR	localhost
123.31.34.240	PTR	localhost
123.31.34.245	PTR	localhost
123.31.35.21	PTR	localhost
123.31.35.23	PTR	localhost
123.31.35.24	PTR	localhost
123.31.35.40	PTR	localhost
123.31.35.55	PTR	localhost
123.31.35.55	A	secureidcmb.vnptdata.vn
123.31.35.57	PTR	localhost
123.31.35.57	A	secureidcmb.vnptdata.vn
123.31.35.68	PTR	localhost
123.31.35.77	PTR	localhost
123.31.35.83	A	minevi.com
123.31.35.83	A	mine247.net
123.31.35.108	PTR	localhost
123.31.35.109	PTR	localhost
123.31.35.128	PTR	localhost
123.31.35.129	PTR	localhost
123.31.35.129	A	beem.vn
123.31.35.164	PTR	localhost
123.31.35.172	PTR	localhost
123.31.35.215	PTR	localhost