Robtex

Up: 81.31.16.0/20
Can't show all results, try to descend to a more specific CIDR
Down left: 81.31.16.0/22
Down right: 81.31.20.0/22

IP	Type	Hostname
81.31.16.1	PTR	g1.4consult.cz
81.31.16.2	PTR	ryby.4consult.cz
81.31.16.2	A	mail.4consult.cz
81.31.16.2	A	mail.kuca.info
81.31.16.23	A	*.4call.net
81.31.16.25	A	gibik.4consult.cz
81.31.16.27	A+PTR	cinan.4consult.cz
81.31.16.28	A+PTR	fazer.4consult.cz
81.31.16.29	A	sypac.4consult.cz
81.31.16.49	PTR	panter-praha.cz
81.31.16.202	A	hyb5.dokument.cz
81.31.22.2	A	ns3.s.cz
81.31.22.18	A	czfree.eu
81.31.22.70	A	confluence.reachlocal.com