Robtex

Up: 123.243.216.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 123.243.220.0/23
Down right: 123.243.222.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
123.243.220.118	PTR	123-243-220-118.tpgi.com.au
123.243.220.217	A+PTR	123-243-220-217.tpgi.com.au
123.243.220.217	A	mail.wbit.com.au
123.243.221.16	A+PTR	123-243-221-16.tpgi.com.au
123.243.221.26	A+PTR	123-243-221-26.tpgi.com.au
123.243.221.48	A+PTR	123-243-221-48.tpgi.com.au
123.243.221.52	PTR	123-243-221-52.tpgi.com.au
123.243.221.115	A+PTR	123-243-221-115.tpgi.com.au
123.243.221.139	A+PTR	123-243-221-139.tpgi.com.au
123.243.221.151	A+PTR	123-243-221-151.tpgi.com.au
123.243.221.152	PTR	123-243-221-152.tpgi.com.au
123.243.221.164	A+PTR	123-243-221-164.tpgi.com.au
123.243.221.168	A+PTR	123-243-221-168.tpgi.com.au
123.243.221.216	PTR	123-243-221-216.tpgi.com.au
123.243.222.4	A	123-243-222-4.tpgi.com.au
123.243.222.22	A	123-243-222-22.tpgi.com.au
123.243.222.74	A	123-243-222-74.tpgi.com.au
123.243.222.75	A	mail.transcorpaustralia.com.au
123.243.222.98	A	123-243-222-98.tpgi.com.au
123.243.222.122	A+PTR	123-243-222-122.tpgi.com.au
123.243.222.122	A	ns1.hillside-computers.com
123.243.222.122	A	ns2.hillside-computers.com
123.243.222.185	A+PTR	123-243-222-185.tpgi.com.au
123.243.223.1	A+PTR	123-243-223-1.static.tpgi.com.au
123.243.223.35	A+PTR	123-243-223-35.static.tpgi.com.au
123.243.223.38	A+PTR	123-243-223-38.static.tpgi.com.au
123.243.223.42	A+PTR	123-243-223-42.static.tpgi.com.au
123.243.223.57	A+PTR	123-243-223-57.static.tpgi.com.au
123.243.223.172	A+PTR	123-243-223-172.static.tpgi.com.au
123.243.223.214	A+PTR	123-243-223-214.static.tpgi.com.au
123.243.223.230	A	hedders.net