Robtex

Up: 209.23.100.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 209.23.100.0/25
Down right: 209.23.100.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
209.23.100.12	PTR	webmail.nicholville.com
209.23.100.12	A	nicholville.com
209.23.100.12	A	humanitiesandtechnology.org
209.23.100.139	PTR	139-100-23-209-cust.slic.com
209.23.100.139	A	wtp-du3-139.slic.com