Robtex

Up: 81.177.144.0/20
Can't show all results, try to descend to a more specific CIDR
Down left: 81.177.144.0/22
Down right: 81.177.148.0/22
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
81.177.144.24	A	sape-context.ru
81.177.144.64	PTR	rnd.post.ru
81.177.144.69	A+PTR	mail.minvodymsc.ru
81.177.144.75	A+PTR	msc.tomsk.ru
81.177.144.78	A+PTR	mail.cgppost.ru
81.177.144.120	A	kalmpost.ru
81.177.144.120	A	exchange.kalmpost.ru
81.177.144.121	PTR	exchange.tverufps.ru
81.177.144.122	A	ns.tverpost.ru
81.177.144.123	A	mail.tverpost.ru
81.177.144.128	A	kav.fpco.ru
81.177.144.129	A	kavv.fpco.ru
81.177.144.130	A+PTR	post1.fpco.ru
81.177.144.131	A	ns.fpco.ru
81.177.144.147	A+PTR	mail.kchrufps.ru
81.177.144.147	A	ns.kchrufps.ru
81.177.144.151	A+PTR	smtp.ipn.ru
81.177.144.151	A	ns2.ipn.ru
81.177.144.159	A	bryanskpost.ru
81.177.144.159	A	test.bryanskpost.ru
81.177.144.159	A	mx.bryanskpost.ru
81.177.144.162	A	proxy-rtcom.postrm.ru
81.177.144.164	A+PTR	post.rtcomm.ru
81.177.144.166	A	nnpost.ru
81.177.144.167	A	proxy.nnpost.ru
81.177.144.169	A+PTR	mx.tuvapost.ru
81.177.144.172	A+PTR	mx.ufps-mo.ru
81.177.144.177	PTR	mail.komiufps.ru
81.177.144.178	A	komiufps.ru
81.177.144.184	A+PTR	ufps.stavropol.ru
81.177.144.184	A	gw.ufps.stavropol.ru
81.177.144.186	A+PTR	volgufps.ru
81.177.144.190	A	kspd.khabpost.ru
81.177.144.212	PTR	kbrpost.ru
81.177.144.212	A	smtp.kbrpost.ru
81.177.144.212	A	ns.kbrpost.ru
81.177.144.225	A	mail.ural-post.ru
81.177.144.230	A+PTR	ext1.maripost.ru
81.177.144.230	A	ns3.maripost.ru
81.177.144.230	A	maripost.ru
81.177.144.231	PTR	ext2.maripost.ru
81.177.144.235	A+PTR	mail1.yktpost.ru
81.177.144.235	A	aat.yktpost.ru
81.177.144.242	A	mail.post.kosnet.ru
81.177.144.242	A	post.kosnet.ru
81.177.146.132	PTR	mskns1.tieto.com
81.177.146.133	PTR	mskns2.tieto.com
81.177.146.169	A	sa-g13.ru
81.177.146.204	A+PTR	relay.i-gorod.com
81.177.147.34	PTR	fort.quik.ru
81.177.147.35	PTR	lord.quik.ru
81.177.150.0	PTR	unknown.eserver-ru.com
81.177.150.2	PTR	unknown.eserver-ru.com
81.177.150.11	PTR	unknown.eserver-ru.com
81.177.150.17	PTR	unknown.eserver-ru.com
81.177.150.40	PTR	unknown.eserver-ru.com
81.177.150.41	PTR	unknown.eserver-ru.com
81.177.150.43	PTR	unknown.eserver-ru.com
81.177.150.49	PTR	unknown.eserver-ru.com
81.177.150.57	PTR	unknown.eserver-ru.com
81.177.150.67	PTR	unknown.eserver-ru.com
81.177.150.74	PTR	unknown.eserver-ru.com
81.177.150.80	PTR	unknown.eserver-ru.com
81.177.150.81	PTR	mail.yatv.ru
81.177.150.89	PTR	unknown.eserver-ru.com
81.177.150.91	PTR	front.sotmarket.ru
81.177.150.97	PTR	unknown.eserver-ru.com
81.177.150.105	PTR	unknown.eserver-ru.com
81.177.150.130	PTR	unknown.eserver-ru.com
81.177.150.137	PTR	unknown.eserver-ru.com
81.177.150.144	PTR	unknown.eserver-ru.com
81.177.150.147	PTR	unknown.eserver-ru.com
81.177.150.160	PTR	unknown.eserver-ru.com
81.177.150.171	PTR	unknown.eserver-ru.com
81.177.150.176	PTR	unknown.eserver-ru.com
81.177.150.179	PTR	unknown.eserver-ru.com
81.177.150.185	PTR	unknown.eserver-ru.com
81.177.150.192	PTR	unknown.eserver-ru.com
81.177.150.194	PTR	unknown.eserver-ru.com
81.177.150.201	PTR	unknown.eserver-ru.com
81.177.150.209	PTR	unknown.eserver-ru.com
81.177.150.224	PTR	unknown.eserver-ru.com
81.177.150.226	PTR	unknown.eserver-ru.com
81.177.150.227	PTR	unknown.eserver-ru.com
81.177.150.233	PTR	unknown.eserver-ru.com
81.177.150.240	PTR	unknown.eserver-ru.com
81.177.150.242	PTR	unknown.eserver-ru.com
81.177.150.243	PTR	unknown.eserver-ru.com
81.177.150.248	PTR	unknown.eserver-ru.com
81.177.150.249	PTR	unknown.eserver-ru.com