Robtex

Up: 81.23.128.0/18
Can't show all results, try to descend to a more specific CIDR
Down left: 81.23.160.0/20
Down right: 81.23.176.0/20
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
81.23.160.0	PTR	u3-0-160-0-00.pool.fecity.ru
81.23.164.0	PTR	u3-0-164-0-00.pool.fecity.ru
81.23.168.0	PTR	u3-0-168-0-00.pool.fecity.ru
81.23.169.238	A	u1-238-169-591-67.pool.fecity.ru
81.23.172.0	PTR	u3-0-172-0-00.pool.fecity.ru
81.23.172.250	A	xn----dtbqnpa5at5a.xn--p1ai
81.23.172.250	A	xn--80ahc5ahagz8b.xn--p1ai
81.23.172.250	A	xn----7sblgllksgxv9b.xn--p1ai
81.23.174.35	PTR	u5-35-174-334-67.pool.fecity.ru
81.23.175.0	PTR	u3-0-175-0-00.pool.fecity.ru
81.23.176.10	A	forum.tlt.ru
81.23.176.10	A	media.srv.tlt.ru
81.23.176.10	A	srv.tlt.ru
81.23.178.97	PTR	host-81-23-178-97.tlt.ru
81.23.178.130	PTR	host-81-23-178-130.tlt.ru
81.23.178.130	A	mail.art-doc.ru
81.23.178.130	A	mail.libavtograd.ru
81.23.178.131	PTR	host-81-23-178-131.tlt.ru
81.23.178.162	PTR	mail.akom.su
81.23.178.163	PTR	host-81-23-178-163.tlt.ru
81.23.178.163	A	mail.akom.su
81.23.178.170	A	mail.akom.su
81.23.179.41	PTR	host-81-23-179-41.tlt.ru
81.23.179.51	A	ns1.mcfbs.ru
81.23.179.51	A	mail.mcfbs.ru
81.23.179.140	PTR	host-81-23-179-140.tlt.ru
81.23.179.140	A	xn----7sbsvxnbd.xn--p1ai
81.23.179.221	PTR	host-81-23-179-221.tlt.ru
81.23.180.70	A	p1platform.ru
81.23.186.14	A	ns2.lso-vaz.ru
81.23.186.14	A	mail.lso-vaz.ru
81.23.186.20	A	mail5.slik.com.ru
81.23.186.34	A+PTR	tzto.com.ru
81.23.186.34	A	mail2.tzto.com.ru
81.23.186.34	A	ns1.tzto.com.ru
81.23.186.47	A	ns2.groupdsk.ru
81.23.186.140	A	tpp.dvrdns.org
81.23.186.142	A	ns2.ecotred.ru
81.23.186.143	A	ns2.ecotred.ru
81.23.186.143	A	mail.ecotred.ru
81.23.186.180	A	mail.megalada.com
81.23.186.186	A	techwik.ru
81.23.186.186	A	www.techwik.ru
81.23.187.24	A	il.ukirs.ru
81.23.187.24	A	il.biznes-lada.ru
81.23.187.24	A	mail.btserv.ru
81.23.187.34	A	mail2.hyundai-arena.ru
81.23.187.57	A	tdprocash.ru
81.23.187.57	A	mx1.tdprocash.ru
81.23.187.57	A	ns1.tdprocash.ru
81.23.187.102	A	mail.taya-auto.ru
81.23.187.102	A	mail4.mir-avto.ru
81.23.187.108	A	mail.taya-auto.ru
81.23.187.116	A	portal-parts.ru
81.23.187.133	A	ns1.groupdsk.ru
81.23.187.133	A	mail.groupdsk.ru
81.23.187.133	A	groupdsk.ru
81.23.187.169	A	mail.zip.ru
81.23.187.169	A	zip.ru
81.23.187.175	A	vrfc.ru
81.23.187.180	A	mx2.tyre-pv.ru
81.23.187.195	A	hccars.ru
81.23.188.196	A+PTR	mx2.avtozerkala.com
81.23.191.234	A	ruli24.ru
81.23.191.234	A	ilbank.ru
81.23.191.234	A	xn--24-vlclys.xn--p1ai