Robtex

Up: 188.133.144.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 188.133.144.0/23
Down right: 188.133.146.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
188.133.144.106	A+PTR	mail.sibsoc.ru
188.133.144.106	A	ns.sibsoc.com
188.133.144.106	A	ns.sibsoc.ru
188.133.146.50	PTR	mail.altaigazprom.ru
188.133.146.134	PTR	mail.tg-alterra.ru
188.133.146.234	PTR	office.a-dn.ru