Robtex

Up: 209.135.0.0/18
Can't show all results, try to descend to a more specific CIDR
Down left: 209.135.0.0/20
Down right: 209.135.16.0/20

IP	Type	Hostname
209.135.0.0	PTR	209.135.0.0
209.135.9.2	PTR	209.135.9.2
209.135.16.255	PTR	209.135.16.255
209.135.20.255	PTR	209.135.20.255
209.135.24.4	PTR	xqn.weakj.com
209.135.30.2	PTR	209.135.30.2
209.135.31.255	PTR	209.135.31.255