Robtex

Up: 208.68.128.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 208.68.129.0/25
Down right: 208.68.129.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
208.68.129.3	PTR	mail2.pbgc.gov
208.68.129.20	A	pbgc.net
208.68.129.20	A	www.pbgc.com
208.68.129.20	A	pbgc.us
208.68.129.51	A+PTR	wilbc1.pbgc.gov
208.68.129.53	A+PTR	wilbc2.pbgc.gov
208.68.129.142	A+PTR	mail2.pbgc.gov