Robtex

Up: 81.17.64.0/19
Can't show all results, try to descend to a more specific CIDR
Down left: 81.17.80.0/21
Down right: 81.17.88.0/21
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
81.17.81.142	A+PTR	mx1.uniser.az
81.17.81.142	A	mail.forward-cargo.az
81.17.81.142	A	mail.uniser.az
81.17.81.187	PTR	cecc.az
81.17.82.12	PTR	cache.google.com
81.17.82.12	A	r1.sn-c53uxax3vh-btqe.googlevideo.com
81.17.82.13	PTR	cache.google.com
81.17.82.13	A	r2.sn-c53uxax3vh-btqe.googlevideo.com
81.17.82.14	PTR	cache.google.com
81.17.82.14	A	r3.sn-c53uxax3vh-btqe.googlevideo.com
81.17.82.15	PTR	cache.google.com
81.17.82.15	A	r4.sn-c53uxax3vh-btqe.googlevideo.com
81.17.82.16	PTR	cache.google.com
81.17.82.16	A	r5.sn-c53uxax3vh-btqe.googlevideo.com
81.17.82.17	PTR	cache.google.com
81.17.82.17	A	r6.sn-c53uxax3vh-btqe.googlevideo.com
81.17.82.18	PTR	cache.google.com
81.17.82.18	A	r7.sn-c53uxax3vh-btqe.googlevideo.com
81.17.82.19	PTR	cache.google.com
81.17.82.19	A	r8.sn-c53uxax3vh-btqe.googlevideo.com
81.17.83.66	A	mail.agl.az
81.17.84.10	A	mail2.khazar.org
81.17.84.10	A	smtp.khazar.org
81.17.84.10	A	pop3.khazar.org
81.17.84.128	PTR	dial-up128-84.bakinter.net
81.17.84.130	PTR	dial-up130-84.bakinter.net
81.17.86.81	PTR	mail.alfa-audit.com
81.17.86.81	A	mail1.alfa-audit.com
81.17.87.234	A	dnsbaku.com
81.17.89.71	A+PTR	webmail.renaissance-palace.com
81.17.89.71	A	webmail.davincihotel.az
81.17.89.71	A	mail.davincihotel.az
81.17.90.49	A	mail.megaaz.com
81.17.90.86	PTR	mail6.bakitelekom.az
81.17.90.138	A	ns2.office.az
81.17.90.138	A	mail2.office.az
81.17.90.253	A	gerayzade.com
81.17.93.2	A+PTR	mx1.memorialklinik.az
81.17.93.3	PTR	mx2.memorialklinik.az
81.17.93.3	A	memorialklinik.az
81.17.93.3	A	www.memorialklinik.az
81.17.93.142	A+PTR	mail.atatravel.az
81.17.94.50	A+PTR	mail.danx.gov.az
81.17.95.242	A	et01.pitscloud.com