Robtex

Up: 123.243.0.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 123.243.0.0/23
Down right: 123.243.2.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
123.243.0.127	PTR	123-243-0-127.static.tpgi.com.au
123.243.0.127	A	mail1.toprydecity.com.au
123.243.0.135	PTR	123-243-0-135.static.tpgi.com.au
123.243.0.203	PTR	123-243-0-203.static.tpgi.com.au
123.243.1.6	A+PTR	123-243-1-6.static.tpgi.com.au
123.243.1.18	A+PTR	123-243-1-18.static.tpgi.com.au
123.243.1.78	PTR	123-243-1-78.static.tpgi.com.au
123.243.1.78	A	mail.nmaccty.net
123.243.1.142	PTR	123-243-1-142.tpgi.com.au
123.243.1.142	A	mail2.aspireddesigns.net
123.243.1.142	A	mail.aspireddesigns.net
123.243.1.145	PTR	123-243-1-145.tpgi.com.au
123.243.1.145	A	mail.ameliakirkby.com
123.243.1.145	A	mail.mcleanclinicalconsulting.com
123.243.1.178	PTR	www.hugin.com.au
123.243.1.178	A	mpirephotography.com
123.243.1.178	A	123-243-1-178.static.tpgi.com.au
123.243.1.194	A	thehutchingsfamily.com
123.243.1.211	A	123-243-1-211.static.tpgi.com.au
123.243.1.237	PTR	123-243-1-237.static.tpgi.com.au
123.243.1.237	A	remote.rmapl.com.au
123.243.1.246	PTR	123-243-1-246.static.tpgi.com.au
123.243.2.161	PTR	123-243-2-161.static.tpgi.com.au
123.243.3.37	PTR	123-243-3-37.static.tpgi.com.au
123.243.3.37	A	mail.tricorpservices.com.au
123.243.3.40	PTR	123-243-3-40.static.tpgi.com.au
123.243.3.40	A	mail.cepu.org
123.243.3.84	PTR	123-243-3-84.static.tpgi.com.au
123.243.3.84	A	mx02.cmrc.com.au
123.243.3.109	PTR	123-243-3-109.static.tpgi.com.au
123.243.3.109	A	dxnaus.com.au
123.243.3.156	A+PTR	123-243-3-156.static.tpgi.com.au
123.243.3.170	A+PTR	mail.iisnet.com.au