Robtex

Up: 199.20.36.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 199.20.36.0/25
Down right: 199.20.36.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
199.20.36.1	A+PTR	nachfwasa01.ogilvy.com
199.20.36.1	A+PTR	mobilehub.ord.ogilvy.com
199.20.36.31	PTR	teamunilevershopper.com
199.20.36.31	PTR	chicago-ams.geometry.com
199.20.36.31	A+PTR	chi-portal-dr.ogilvy.com
199.20.36.61	PTR	chi.redworks.com
199.20.36.61	A	nchi1mcl05.ogilvy.com
199.20.36.68	A	chi.redworks.com
199.20.36.123	A+PTR	myofficechi.ogilvy.com
199.20.36.174	A	arc.ogilvy.com
199.20.36.242	A	e.l.ogilvy.com