Robtex

Up: 81.187.40.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 81.187.44.0/23
Down right: 81.187.46.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
81.187.44.0	A+PTR	0.44.187.81.in-addr.arpa
81.187.44.9	A	allcorn.org
81.187.44.22	PTR	storage2.netaware.org.uk
81.187.44.22	A	mail.netaware.org.uk
81.187.44.23	PTR	81.187.44.23
81.187.44.23	A	mail.proaudio.org.uk
81.187.44.50	PTR	81.187.44.50
81.187.44.52	PTR	81.187.44.52
81.187.44.55	A	55.44.187.81.in-addr.arpa
81.187.44.62	A+PTR	albert.morsing.cc
81.187.44.62	A	mail2.morsing.cc
81.187.44.62	A	ns2.morsing.cc
81.187.44.99	A+PTR	stanley.jellybaby.net
81.187.44.99	A	iced.jellybaby.net
81.187.44.136	A	136.44.187.81.in-addr.arpa
81.187.44.161	A	161.44.187.81.in-addr.arpa
81.187.44.177	A	fb.playon.it
81.187.44.180	A	fred.playon.it
81.187.44.196	A	196.44.187.81.in-addr.arpa
81.187.44.213	A	213.44.187.81.in-addr.arpa
81.187.44.222	A	222.44.187.81.in-addr.arpa
81.187.44.241	A	basicmonkey.cc
81.187.44.242	PTR	81.187.44.242
81.187.44.242	A	bix.cc
81.187.45.0	A+PTR	0.45.187.81.in-addr.arpa
81.187.45.10	A+PTR	pifeed24.bgcomp.co.uk
81.187.45.14	PTR	cisco2.bgcomp.co.uk
81.187.45.33	A	g2track.com
81.187.45.99	A	chirundu.co.uk
81.187.45.142	PTR	aye.ultralinear.co.uk
81.187.45.142	A	v4ns1.enyc.org.uk
81.187.45.142	A	dns2.enyc.org.uk
81.187.45.184	A	ns1.blackery.net
81.187.46.0	A+PTR	0.46.187.81.in-addr.arpa
81.187.46.35	PTR	www.smartsourcing.plc.uk
81.187.46.35	A	itcontractpages.com
81.187.46.70	PTR	70.46.187.81.in-addr.arpa
81.187.46.70	A	3g.dryiceuk.com
81.187.46.73	A	mail-e.metalfinishingsltd.co.uk
81.187.46.128	A	network.bettger.net
81.187.46.130	A+PTR	mx1.bettger.net
81.187.46.131	A+PTR	ns1.bettger.net
81.187.46.132	A+PTR	ns2.bettger.net
81.187.46.135	A	broadcast.bettger.net
81.187.46.156	A	vodden.com
81.187.46.189	A	mail.totheinternet.eu
81.187.46.189	A	mail.telephone.exchange
81.187.46.189	A	mail.wexwoo.com
81.187.46.203	A	resolver1.honeyborough.org.uk
81.187.46.208	A+PTR	finneys.me.uk
81.187.46.208	PTR	mail.finneys.me.uk
81.187.46.239	PTR	81.187.46.239
81.187.47.0	A+PTR	0.47.187.81.in-addr.arpa
81.187.47.7	A	philrider.co.uk
81.187.47.55	PTR	81.187.47.55
81.187.47.99	A+PTR	mail.faste-mail.net
81.187.47.99	A	mail.towerhousehorses.com
81.187.47.100	A+PTR	smtp.faste-mail.net
81.187.47.100	A+PTR	www.faste-mail.net
81.187.47.124	PTR	81.187.47.124
81.187.47.124	A	mail.vsssouthsudan.com
81.187.47.124	A	vss.dnsalias.net
81.187.47.164	A	164.47.187.81.in-addr.arpa
81.187.47.170	A+PTR	170.47.187.81.in-addr.arpa
81.187.47.195	A	195.47.187.81.in-addr.arpa
81.187.47.212	A+PTR	pool12.paradisegreen.co.uk
81.187.47.249	A	249.47.187.81.in-addr.arpa
81.187.47.254	PTR	81.187.47.254
81.187.47.254	A	srv03.thecateringbutcher.co.uk