Robtex

Up: 123.243.100.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 123.243.100.0/25
Down right: 123.243.100.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
123.243.100.17	A+PTR	123-243-100-17.tpgi.com.au
123.243.100.68	A	secure.imperialcrest.com.au
123.243.100.94	A+PTR	123-243-100-94.tpgi.com.au
123.243.100.124	A+PTR	123-243-100-124.tpgi.com.au
123.243.100.143	A	123-243-100-143.tpgi.com.au
123.243.100.181	PTR	undercat.net
123.243.100.181	A	mail.undercat.net
123.243.100.181	A	trup16.net
123.243.100.187	PTR	123-243-100-187.tpgi.com.au
123.243.100.187	A	mailbox.amgcad.com
123.243.100.208	A	slyfox.net.au
123.243.100.214	A	123-243-100-214.tpgi.com.au
123.243.100.220	A	123-243-100-220.tpgi.com.au