Robtex

Up: 91.232.24.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 91.232.28.0/23
Down right: 91.232.30.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
91.232.28.18	PTR	dc-3b7bc211-mail.voltairenet.org
91.232.28.22	PTR	server.voltairenet.org
91.232.28.110	PTR	static.tagemes.net
91.232.28.110	A	dc-a0ad932e8378.marafonbetcasino.ru
91.232.29.3	PTR	3.29.232.91.static.server.ua
91.232.29.30	PTR	30.29.232.91.static.server.ua
91.232.29.83	PTR	83.29.232.91.static.server.ua
91.232.29.85	PTR	85.29.232.91.static.server.ua
91.232.29.85	A	jioptuym.com
91.232.29.106	PTR	106.29.232.91.static.server.ua
91.232.29.106	A	taxes.instanthq.com
91.232.29.174	PTR	174.29.232.91.static.server.ua
91.232.30.6	PTR	6.30.232.91.static.server.ua
91.232.30.24	PTR	24.30.232.91.static.server.ua
91.232.30.54	PTR	54.30.232.91.static.server.ua
91.232.30.169	PTR	parallel.conasody.com
91.232.30.242	A	mycanadastore.com
91.232.30.243	PTR	243.30.232.91.static.server.ua
91.232.30.243	A	ns1.dnsdaemon.com
91.232.30.244	PTR	244.30.232.91.static.server.ua
91.232.30.244	A	ns2.dnsdaemon.com
91.232.30.245	PTR	245.30.232.91.static.server.ua
91.232.30.245	A	dnsdaemon.com
91.232.30.245	A	mail.dnsdaemon.com
91.232.30.249	A	mail.rx-prime.com
91.232.30.249	A	mail.lineronline.com
91.232.30.249	A	lineronline.com
91.232.31.14	PTR	14.31.232.91.static.server.ua
91.232.31.15	PTR	15.31.232.91.static.server.ua
91.232.31.22	PTR	22.31.232.91.static.server.ua
91.232.31.22	A	nodeads.com
91.232.31.35	PTR	35.31.232.91.static.server.ua
91.232.31.35	A	mail.profi-instrument.com
91.232.31.35	A	mail.metabo-online.ua
91.232.31.37	A	instrument.zp.ua
91.232.31.37	A	www.instrument.zp.ua
91.232.31.38	PTR	38.31.232.91.static.server.ua
91.232.31.38	A	sunduk.ua
91.232.31.65	PTR	65.31.232.91.static.server.ua
91.232.31.87	PTR	87.31.232.91.static.server.ua
91.232.31.167	PTR	167.31.232.91.static.server.ua
91.232.31.202	PTR	202.31.232.91.static.server.ua
91.232.31.204	PTR	204.31.232.91.static.server.ua
91.232.31.215	PTR	215.31.232.91.static.server.ua
91.232.31.245	PTR	245.31.232.91.static.novalayer.net