Robtex

Up: 203.13.16.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 203.13.16.0/25
Down right: 203.13.16.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
203.13.16.0	PTR	blackice-netblock
203.13.16.1	PTR	blackice.com.au
203.13.16.1	A	writingtolearn.net
203.13.16.1	A	turingevolved.com
203.13.16.2	A	suppressed.blackice.com.au
203.13.16.17	PTR	astraldynamics.com
203.13.16.17	A	ns2.blackice.com.au
203.13.16.51	PTR	david
203.13.16.214	A+PTR	host214.blackice.com.au
203.13.16.253	PTR	host253.blackice.com.au
203.13.16.253	A	mail.blackice.com.au
203.13.16.254	A	host254.blackice.com.au