Robtex

Up: 192.43.172.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 192.43.172.0/25
Down right: 192.43.172.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
192.43.172.1	A	gw.i.nstld.com
192.43.172.9	A	vrrp.i.nstld.com
192.43.172.10	A	igw1.i.nstld.com
192.43.172.11	A	igw2.i.nstld.com
192.43.172.30	A+PTR	i.gtld-servers.net
192.43.172.30	A	ns1.froggyreviews.com
192.43.172.30	A	i.edu-servers.net
192.43.172.31	A+PTR	i2.nstld.com
192.43.172.32	PTR	i3.nstld.com
192.43.172.33	PTR	i4.nstld.com
192.43.172.34	A+PTR	i5.nstld.com
192.43.172.35	A+PTR	i6.nstld.com
192.43.172.36	A+PTR	i7.nstld.com
192.43.172.37	A+PTR	i8.nstld.com
192.43.172.38	PTR	i9.nstld.com
192.43.172.39	A+PTR	i10.nstld.com