Robtex

Up: 157.240.236.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 157.240.236.0/25
Down right: 157.240.236.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
157.240.236.2	A	video-frx5-2.xx.fbcdn.net
157.240.236.15	PTR	edge-star-shv-02-frx5.facebook.com
157.240.236.15	A	ffbymail.com
157.240.236.15	A	facebookappmail.com
157.240.236.35	A	fbsbx.com
157.240.236.39	A	fd3a9efa880kislnjiy-hajaqqmo1490586913-sonar.xz.fbcdn.net
157.240.236.39	A	f3220413480kdno4pyq-duijgpwx1503982160-sonar.xz.fbcdn.net
157.240.236.174	PTR	instagram-p42-shv-02-frx5.fbcdn.net