Robtex

Up: 81.21.176.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 81.21.180.0/23
Down right: 81.21.182.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
81.21.181.53	A	featurelvs.schoolmaster.nl
81.21.182.68	PTR	main-e2e.zentest.nl
81.21.182.68	A+PTR	test1.zentest.nl
81.21.182.68	PTR	dnn.zentest.nl
81.21.182.69	A+PTR	services.zentest.nl
81.21.182.69	PTR	*.smnsqldev1.zentest.nl
81.21.182.69	PTR	*.smnsqldev.zentest.nl
81.21.182.91	A	services.zentest.nl
81.21.182.94	A	zentest.nl
81.21.183.34	A+PTR	smnexchange1.schoolmaster.nl
81.21.183.35	A	sm-exchange.schoolmaster.nl
81.21.183.36	A+PTR	smnexchange1.schoolmaster.nl
81.21.183.36	PTR	webmail.schoolmaster.nl