Robtex

Up: 192.31.80.0/22
Can't show all results, try to descend to a more specific CIDR
Down left: 192.31.80.0/24
Down right: 192.31.81.0/24

IP	Type	Hostname
192.31.80.1	A	gw.d.nstld.com
192.31.80.9	A+PTR	vrrp.d.nstld.com
192.31.80.10	A+PTR	igw1.d.nstld.com
192.31.80.11	A	igw2.d.nstld.com
192.31.80.30	A+PTR	d.gtld-servers.net
192.31.80.30	A	d.gtld-servers.com
192.31.80.30	A	d.edu-servers.net
192.31.80.31	PTR	d2.nstld.com
192.31.80.31	A	d2.gov-servers.net
192.31.80.32	PTR	d3.nstld.com
192.31.80.32	A+PTR	indigo.arin.net
192.31.80.33	PTR	d4.nstld.com
192.31.80.34	PTR	ns4.dnsmanaged.com
192.31.80.35	PTR	d6.nstld.com
192.31.80.36	PTR	d.edu-servers.net