Robtex

Up: 5.81.0.0/16
Can't show all results, try to descend to a more specific CIDR
Down left: 5.81.128.0/18
Down right: 5.81.192.0/18

IP	Type	Hostname
5.81.128.0	PTR	host5-81-128-0.range5-81.btcentralplus.com
5.81.129.104	A	host5-81-129-104.range5-81.btcentralplus.com
5.81.131.79	A	host5-81-131-79.range5-81.btcentralplus.com
5.81.131.99	A	host5-81-131-99.range5-81.btcentralplus.com
5.81.132.53	A	host5-81-132-53.range5-81.btcentralplus.com
5.81.132.184	A	host5-81-132-184.range5-81.btcentralplus.com
5.81.133.11	A	host5-81-133-11.range5-81.btcentralplus.com
5.81.135.146	A	www.andrewgasson.com
5.81.135.169	A	host5-81-135-169.range5-81.btcentralplus.com
5.81.135.202	A	andrewgasson.com
5.81.135.231	A	host5-81-135-231.range5-81.btcentralplus.com
5.81.137.194	A	host5-81-137-194.range5-81.btcentralplus.com
5.81.137.218	A	wizardvideo.no-ip.org
5.81.138.55	A	host5-81-138-55.range5-81.btcentralplus.com
5.81.139.20	A	whyatt.dyndns.org
5.81.143.188	A	host5-81-143-188.range5-81.btcentralplus.com
5.81.148.144	A	ns1.bite.it
5.81.148.172	A	host5-81-148-172.range5-81.btcentralplus.com
5.81.149.190	A	host5-81-149-190.range5-81.btcentralplus.com
5.81.150.152	A	host5-81-150-152.range5-81.btcentralplus.com
5.81.150.253	A	host5-81-150-253.range5-81.btcentralplus.com
5.81.151.255	A	host5-81-151-255.range5-81.btcentralplus.com
5.81.154.70	A	host5-81-154-70.range5-81.btcentralplus.com
5.81.157.40	A	ayvaparmar.com
5.81.157.178	A	host5-81-157-178.range5-81.btcentralplus.com
5.81.158.38	A	host5-81-158-38.range5-81.btcentralplus.com
5.81.158.251	A	host5-81-158-251.range5-81.btcentralplus.com
5.81.160.53	A	benopenshaw.com
5.81.160.153	A	host5-81-160-153.range5-81.btcentralplus.com
5.81.160.217	A	host5-81-160-217.range5-81.btcentralplus.com
5.81.160.254	A	host5-81-160-254.range5-81.btcentralplus.com
5.81.161.160	A	host5-81-161-160.range5-81.btcentralplus.com
5.81.162.111	A	host5-81-162-111.range5-81.btcentralplus.com
5.81.164.115	A	host5-81-164-115.range5-81.btcentralplus.com
5.81.164.230	A	host5-81-164-230.range5-81.btcentralplus.com
5.81.165.79	A	host5-81-165-79.range5-81.btcentralplus.com
5.81.168.152	A	host5-81-168-152.range5-81.btcentralplus.com
5.81.168.204	A	host5-81-168-204.range5-81.btcentralplus.com
5.81.169.115	A	host5-81-169-115.range5-81.btcentralplus.com
5.81.169.192	A	grahamsoft.co.uk
5.81.170.116	A	host5-81-170-116.range5-81.btcentralplus.com
5.81.171.3	A	happyhere.co.uk
5.81.173.39	A	host5-81-173-39.range5-81.btcentralplus.com
5.81.174.42	A	host5-81-174-42.range5-81.btcentralplus.com
5.81.174.202	A	host5-81-174-202.range5-81.btcentralplus.com
5.81.175.136	A	host5-81-175-136.range5-81.btcentralplus.com
5.81.182.1	A+PTR	host5-81-182-1.range5-81.btcentralplus.com
5.81.182.182	A	host5-81-182-182.range5-81.btcentralplus.com
5.81.184.92	A	monotok.org
5.81.185.60	A	host5-81-185-60.range5-81.btcentralplus.com
5.81.185.72	A	host5-81-185-72.range5-81.btcentralplus.com
5.81.185.72	A	www.monotok.org
5.81.187.126	A	host5-81-187-126.range5-81.btcentralplus.com
5.81.187.144	A	ziller2.dyndns.org
5.81.189.91	A	host5-81-189-91.range5-81.btcentralplus.com
5.81.190.43	A	host5-81-190-43.range5-81.btcentralplus.com
5.81.193.39	A	host5-81-193-39.range5-81.btcentralplus.com
5.81.195.2	A+PTR	host5-81-195-2.range5-81.btcentralplus.com
5.81.195.103	A	host5-81-195-103.range5-81.btcentralplus.com
5.81.196.68	A	host5-81-196-68.range5-81.btcentralplus.com
5.81.197.47	A	host5-81-197-47.range5-81.btcentralplus.com
5.81.197.201	A	host5-81-197-201.range5-81.btcentralplus.com
5.81.198.104	A	host5-81-198-104.range5-81.btcentralplus.com
5.81.198.124	A	host5-81-198-124.range5-81.btcentralplus.com
5.81.199.238	A	a1helmets.com
5.81.204.11	A	host5-81-204-11.range5-81.btcentralplus.com
5.81.204.51	A	host5-81-204-51.range5-81.btcentralplus.com
5.81.205.230	A	host5-81-205-230.range5-81.btcentralplus.com
5.81.209.6	A	host5-81-209-6.range5-81.btcentralplus.com
5.81.210.151	A	host5-81-210-151.range5-81.btcentralplus.com
5.81.211.79	A	host5-81-211-79.range5-81.btcentralplus.com
5.81.213.244	A	host5-81-213-244.range5-81.btcentralplus.com
5.81.213.244	A	mail.compufix-uk-ltd.com
5.81.214.243	A	fbgconsultancy.no-ip.biz
5.81.214.249	A	host5-81-214-249.range5-81.btcentralplus.com
5.81.216.13	A	shakeyrc.com
5.81.216.30	A	host5-81-216-30.range5-81.btcentralplus.com
5.81.217.54	A	host5-81-217-54.range5-81.btcentralplus.com
5.81.217.232	A	host5-81-217-232.range5-81.btcentralplus.com
5.81.217.254	A	host5-81-217-254.range5-81.btcentralplus.com
5.81.218.73	A	host5-81-218-73.range5-81.btcentralplus.com
5.81.218.144	A	mail.promatric.com
5.81.219.32	A	host5-81-219-32.range5-81.btcentralplus.com
5.81.220.32	A	web-invoices.com
5.81.221.224	A	host5-81-221-224.range5-81.btcentralplus.com
5.81.222.105	A	host5-81-222-105.range5-81.btcentralplus.com
5.81.222.132	A	host5-81-222-132.range5-81.btcentralplus.com
5.81.223.2	PTR	host5-81-223-2.range5-81.btcentralplus.com
5.81.225.3	A+PTR	host5-81-225-3.range5-81.btcentralplus.com
5.81.225.17	A	host5-81-225-17.range5-81.btcentralplus.com
5.81.225.188	A	host5-81-225-188.range5-81.btcentralplus.com
5.81.229.195	A	host5-81-229-195.range5-81.btcentralplus.com
5.81.230.244	A	host5-81-230-244.range5-81.btcentralplus.com
5.81.232.63	A	host5-81-232-63.range5-81.btcentralplus.com
5.81.232.177	A	host5-81-232-177.range5-81.btcentralplus.com
5.81.233.146	A	host5-81-233-146.range5-81.btcentralplus.com
5.81.235.101	A	host5-81-235-101.range5-81.btcentralplus.com
5.81.235.234	A	host5-81-235-234.range5-81.btcentralplus.com
5.81.235.237	A	host5-81-235-237.range5-81.btcentralplus.com
5.81.236.97	A	host5-81-236-97.range5-81.btcentralplus.com
5.81.240.185	A	host5-81-240-185.range5-81.btcentralplus.com
5.81.241.135	A	reuben.design
5.81.245.140	A	whisanders.co.uk
5.81.245.224	A	host5-81-245-224.range5-81.btcentralplus.com
5.81.246.120	A	host5-81-246-120.range5-81.btcentralplus.com
5.81.246.148	A	mail.westernskiphire.co.uk
5.81.246.208	A	host5-81-246-208.range5-81.btcentralplus.com
5.81.247.68	A	host5-81-247-68.range5-81.btcentralplus.com
5.81.248.191	A	xn--ta-sarp-7ed.com
5.81.249.100	A	host5-81-249-100.range5-81.btcentralplus.com
5.81.251.172	A	host5-81-251-172.range5-81.btcentralplus.com
5.81.251.254	A	host5-81-251-254.range5-81.btcentralplus.com
5.81.251.255	A	host5-81-251-255.range5-81.btcentralplus.com
5.81.253.62	A	jrshodges.dnsalias.com
5.81.254.158	A	host5-81-254-158.range5-81.btcentralplus.com