Robtex

Up: 81.90.242.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 81.90.243.0/25
Down right: 81.90.243.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
81.90.243.2	A	posta.automeisner.cz
81.90.243.6	PTR	unassigned-81-90-243-6.ujezd.net
81.90.243.6	A	server.adminoffice.cz
81.90.243.6	A	adminoffice.cz
81.90.243.10	PTR	unassigned-81-90-243-10.ujezd.net
81.90.243.14	PTR	unassigned-81-90-243-14.ujezd.net
81.90.243.14	A	mail.aluteckk.cz
81.90.243.23	PTR	unassigned-81-90-243-23.ujezd.net
81.90.243.30	A+PTR	mail.eko-program.cz
81.90.243.30	A	eko-program.cz
81.90.243.30	A	mail.corsin.eu
81.90.243.51	PTR	unassigned-81-90-243-51.ujezd.net
81.90.243.86	PTR	unassigned-81-90-243-86.ujezd.net
81.90.243.98	PTR	unassigned-81-90-243-98.ujezd.net
81.90.243.102	A+PTR	smtp.sevcik.us
81.90.243.102	A	sevcik.us
81.90.243.102	A	www.jirny-living.cz
81.90.243.130	A+PTR	srv01.polar-transport.cz
81.90.243.146	A+PTR	web.sitkhaso.cz
81.90.243.161	PTR	unassigned-81-90-243-161.ujezd.net
81.90.243.161	A	www.zwz.cz
81.90.243.161	A	zwz.cz
81.90.243.195	PTR	smtp.satca.net
81.90.243.202	PTR	unassigned-81-90-243-202.ujezd.net
81.90.243.202	A	server.sitkhaso.cz
81.90.243.203	A+PTR	server2.sitkhaso.cz
81.90.243.210	A	praha.sprint-trading.cz
81.90.243.225	PTR	vhosts.weboutsourcing.cz
81.90.243.238	A	www.stulik.cz
81.90.243.238	A	stulik.cz
81.90.243.255	PTR	unassigned-81-90-243-255.ujezd.net