Robtex

Up: 83.172.16.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 83.172.20.0/23
Down right: 83.172.22.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
83.172.20.1	A+PTR	main.sibinet.com
83.172.20.1	A	ns.sibinet.com
83.172.20.4	PTR	isc.sibinet.com
83.172.20.19	PTR	fibra.sibinet.com
83.172.20.21	PTR	artem.sibinet.com
83.172.20.65	PTR	ucheb-gw.sibinet.com
83.172.20.74	PTR	arts.sibinet.com
83.172.20.74	A	ns2.silviagrandi.com
83.172.20.79	PTR	mail.gsm70.ru
83.172.20.83	PTR	host-83.sibinet.com
83.172.20.93	A	fenixxx.sibinet.com
83.172.20.150	PTR	host-150.sibinet.com
83.172.20.160	PTR	host-160.sibinet.com
83.172.20.231	PTR	host-231.sibinet.com
83.172.21.1	A+PTR	sib-gw.sibinet.com
83.172.21.10	PTR	petroluz.sibinet.com
83.172.21.10	A	novinka.tomsk.ru
83.172.21.19	PTR	kenny.sibinet.com
83.172.21.22	PTR	sasha.sibinet.com
83.172.21.22	A	w-meladze.ru
83.172.21.22	A	www.w-meladze.ru
83.172.21.32	PTR	stone.sibinet.com
83.172.21.32	A	aikido.tom.ru
83.172.21.188	PTR	sib-188.sibinet.com
83.172.21.244	PTR	sib-244.sibinet.com
83.172.22.5	PTR	bov.sibinet.com
83.172.22.6	PTR	host-6.sibinet.com
83.172.22.7	PTR	fastnet-gw.sibinet.com
83.172.22.10	PTR	koban.sibinet.com
83.172.22.13	PTR	host-13.sibinet.com
83.172.22.14	PTR	host-14.sibinet.com
83.172.22.15	PTR	demos.north.sibinet.com
83.172.22.16	PTR	host-16.sibinet.com
83.172.22.19	PTR	sancho.north.sibinet.com
83.172.22.24	PTR	lily.north.sibinet.com
83.172.22.30	PTR	host-30.sibinet.com
83.172.22.36	PTR	host-36.sibinet.com
83.172.22.41	PTR	host-41.sibinet.com
83.172.22.48	PTR	host-48.sibinet.com
83.172.22.49	PTR	host-49.sibinet.com
83.172.22.53	PTR	host-53.sibinet.com
83.172.22.65	PTR	ucheb-gw.sibinet.com
83.172.22.68	PTR	host-68.sibinet.com
83.172.22.69	PTR	host-69.sibinet.com
83.172.22.77	PTR	host-77.sibinet.com
83.172.22.80	PTR	host-80.sibinet.com
83.172.22.82	PTR	host-82.sibinet.com
83.172.22.91	PTR	host-91.sibinet.com
83.172.22.93	PTR	host-93.sibinet.com
83.172.22.94	PTR	host-94.sibinet.com
83.172.22.95	PTR	host-95.sibinet.com
83.172.22.96	PTR	host-96.sibinet.com
83.172.22.100	PTR	host-100.sibinet.com
83.172.22.102	PTR	host-102.sibinet.com
83.172.22.110	PTR	host-110.sibinet.com
83.172.22.111	PTR	host-111.sibinet.com
83.172.22.117	PTR	host-117.sibinet.com
83.172.22.118	PTR	host-118.sibinet.com
83.172.22.122	PTR	host-122.sibinet.com
83.172.22.126	PTR	host-126.sibinet.com
83.172.22.130	PTR	host-130.sibinet.com
83.172.22.135	PTR	host-135.sibinet.com
83.172.22.136	PTR	host-136.sibinet.com
83.172.22.137	PTR	host-137.sibinet.com
83.172.22.144	PTR	host-144.sibinet.com
83.172.22.145	PTR	host-145.sibinet.com
83.172.22.148	PTR	host-148.sibinet.com
83.172.22.149	PTR	host-149.sibinet.com
83.172.22.150	PTR	host-150.sibinet.com
83.172.22.158	PTR	host-158.sibinet.com
83.172.22.159	PTR	host-159.sibinet.com
83.172.22.160	PTR	host-160.sibinet.com
83.172.22.161	PTR	host-161.sibinet.com
83.172.22.163	PTR	host-163.sibinet.com
83.172.22.165	PTR	host-165.sibinet.com
83.172.22.166	PTR	host-166.sibinet.com
83.172.22.172	PTR	host-172.sibinet.com
83.172.22.173	PTR	host-173.sibinet.com
83.172.22.180	PTR	host-180.sibinet.com
83.172.22.183	PTR	host-183.sibinet.com
83.172.22.184	PTR	host-184.sibinet.com
83.172.22.189	PTR	host-189.sibinet.com
83.172.22.190	PTR	host-190.sibinet.com
83.172.22.192	PTR	host-192.sibinet.com
83.172.22.195	PTR	host-195.sibinet.com
83.172.22.196	PTR	fastnet00.sibinet.com
83.172.22.201	PTR	fastnet05.sibinet.com
83.172.22.203	PTR	fastnet07.sibinet.com
83.172.22.215	PTR	fastnet19.sibinet.com
83.172.22.218	PTR	fastnet22.sibinet.com
83.172.22.225	PTR	e-prise.ru
83.172.22.225	PTR	mail.e-prise.ru
83.172.22.225	PTR	enterprise.tomsk.ru
83.172.22.226	PTR	host-226.sibinet.com
83.172.22.234	PTR	host-234.sibinet.com
83.172.22.241	PTR	host-241.sibinet.com
83.172.22.243	PTR	host-243.sibinet.com
83.172.22.248	PTR	host-248.sibinet.com
83.172.22.252	PTR	host-252.sibinet.com
83.172.22.253	PTR	beta.fastnet.sibinet.com
83.172.23.5	PTR	mail.sibinet.com
83.172.23.5	A	sibinet.com
83.172.23.5	A	www.sibinet.com
83.172.23.7	PTR	helios.sibinet.com
83.172.23.8	A+PTR	ns4.sibinet.com
83.172.23.8	A	ns2.chernilki.ru
83.172.23.21	PTR	trixbox0.sibinet.com
83.172.23.65	PTR	ucheb-gw.sibinet.com
83.172.23.150	PTR	host-150.sibinet.com