Robtex

Up: 81.23.160.0/19
Can't show all results, try to descend to a more specific CIDR
Down left: 81.23.160.0/21
Down right: 81.23.168.0/21
(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
81.23.167.240	PTR	u5-240-167-1122-67.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