Robtex

Up: 81.21.172.0/22
Can't show all results, try to descend to a more specific CIDR
Down left: 81.21.174.0/24
Down right: 81.21.175.0/24
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
81.21.174.0	PTR	net.doruk.net.tr
81.21.174.1	PTR	knk.c7.eth.0.5.doruk.net.tr
81.21.174.15	PTR	rev.15.174.21.81.doruk.net.tr
81.21.174.26	PTR	rev.26.174.21.81.doruk.net.tr
81.21.174.35	PTR	ns1.webulkesi.com
81.21.174.37	PTR	ns.sscbilisim.net
81.21.174.37	A	ns1.safkar.com.tr
81.21.174.38	A	mail.webulkesi.net
81.21.174.39	PTR	rev.39.174.21.81.doruk.net.tr
81.21.174.44	PTR	rev.44.174.21.81.doruk.net.tr
81.21.174.55	PTR	rev.55.174.21.81.doruk.net.tr
81.21.174.64	PTR	rev.64.174.21.81.doruk.net.tr
81.21.174.65	PTR	rev.65.174.21.81.doruk.net.tr
81.21.174.66	PTR	rev.66.174.21.81.doruk.net.tr
81.21.174.75	PTR	rev.75.174.21.81.doruk.net.tr
81.21.174.93	PTR	rev.93.174.21.81.doruk.net.tr
81.21.174.99	A	mail.bilginoglu-endustri.com.tr
81.21.174.102	PTR	rev.102.174.21.81.doruk.net.tr
81.21.174.127	PTR	rev.127.174.21.81.doruk.net.tr
81.21.174.183	PTR	rev.183.174.21.81.doruk.net.tr
81.21.174.184	PTR	rev.184.174.21.81.doruk.net.tr
81.21.174.231	PTR	rev.231.174.21.81.doruk.net.tr
81.21.174.255	PTR	bcast.doruk.net.tr
81.21.175.2	PTR	2-175.21.81.doruk.net.tr
81.21.175.2	A	ns1.radius.web.tr
81.21.175.2	A	pvepd.net
81.21.175.3	PTR	radius.web.tr
81.21.175.4	A+PTR	mail.darsateks.com
81.21.175.4	A	mail.hannadarsa.com
81.21.175.5	PTR	ns9.pandoraisp.com
81.21.175.5	A	mail.radiusdns.com
81.21.175.5	A	mail.ferahasm.com
81.21.175.8	PTR	mail.radius.com.tr
81.21.175.8	A	mail.fujitsubilgisayar.com
81.21.175.11	PTR	11-175.21.81.doruk.net.tr
81.21.175.11	A	alertatek.com
81.21.175.11	A	3uyulechengguanfangwang.xcc365.com
81.21.175.15	PTR	15-175.21.81.doruk.net.tr
81.21.175.15	A	ns1.radiusdns.com
81.21.175.20	A	mail.radiusbilgisayar.com
81.21.175.23	PTR	23-175.21.81.doruk.net.tr
81.21.175.23	A	radiusbilgisayar.com
81.21.175.23	A	*.kinota.net
81.21.175.31	PTR	31-175.21.81.doruk.net.tr
81.21.175.32	PTR	32-175.21.81.doruk.net.tr
81.21.175.76	PTR	76-175.21.81.doruk.net.tr
81.21.175.76	A	ns.sokoltarimsal.com.tr
81.21.175.76	A	mail.kofteciramiz.com.tr
81.21.175.115	A+PTR	mail.mercanlarotomotiv.com.tr