Robtex

Up: 203.33.16.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 203.33.20.0/23
Down right: 203.33.22.0/23

IP	Type	Hostname
203.33.20.0	PTR	local.asit.com.au
203.33.20.105	A+PTR	mail.asit.com.au
203.33.20.105	A	mail.tns.com.au
203.33.20.114	A+PTR	intranet.asit.com.au
203.33.20.115	A	ts.asit.com.au
203.33.20.130	A+PTR	smtp.asit.com.au
203.33.20.150	A+PTR	ns1.asit.com.au
203.33.20.150	A	ns1.tns.com.au
203.33.20.153	A	australianitsupport.net.au
203.33.20.161	A	sip.asit.com.au
203.33.20.163	A	av.asit.com.au
203.33.22.0	PTR	203-33-22-0.perm.onsavii.com
203.33.22.3	PTR	203-33-22-3.perm.onsavii.com
203.33.22.35	PTR	203-33-22-35.perm.onsavii.com
203.33.22.137	PTR	domain.not.configured
203.33.22.137	A	mx1.houseofpaul.com.au