Robtex

Up: 81.10.36.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 81.10.36.0/25
Down right: 81.10.36.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
81.10.36.112	PTR	host-81.10.36.112.tedata.net
81.10.36.120	PTR	host-81.10.36.120.tedata.net
81.10.36.150	PTR	host-81.10.36.150.tedata.net
81.10.36.161	A	ns.aspire-sy.com
81.10.36.161	A	mail.aspire-sy.com
81.10.36.161	A	alrehabcity.net
81.10.36.175	PTR	host-81.10.36.175.tedata.net
81.10.36.182	PTR	host-81.10.36.182.tedata.net
81.10.36.233	PTR	host-81.10.36.233.tedata.net
81.10.36.248	PTR	host-81.10.36.248.tedata.net
81.10.36.254	PTR	host-81.10.36.254.tedata.net