Robtex

Up: 157.240.20.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 157.240.21.0/25
Down right: 157.240.21.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
157.240.21.1	A+PTR	edge-fblite-ws-p1-shv-01-cdt1.facebook.com
157.240.21.4	A+PTR	edge-resolver001-bgp-01-cdt1.facebook.com
157.240.21.5	A+PTR	livestream-edgetee-upload-shv-01-cdt1.facebook.com
157.240.21.5	A	edgetee-upload-cdt.xx.fbcdn.net
157.240.21.8	A+PTR	edge-extern-shv-01-cdt1.facebook.com
157.240.21.11	A+PTR	edge-mqtt-shv-01-cdt1.facebook.com
157.240.21.16	A+PTR	edge-star-shv-01-cdt1.facebook.com
157.240.21.16	A	instsagram.com
157.240.21.16	A	fcacebook.com
157.240.21.17	A+PTR	edge-video-shv-01-cdt1.fbcdn.net
157.240.21.17	A	video-cdt.xx.fbcdn.net
157.240.21.17	A	video-cdt1-1.xx.fbcdn.net
157.240.21.18	A+PTR	edge-z-p1-shv-01-cdt1.facebook.com
157.240.21.19	A+PTR	secure-edge-latest-shv-01-cdt1.facebook.com
157.240.21.20	PTR	xx-fbcdn-shv-01-cdt1.fbcdn.net
157.240.21.20	A	fe7b12d3680kdno4pyq-uyzgfbkv1498200125-sonar.xx.fbcdn.net
157.240.21.20	A	fff90f78080kjlfw3yy-rvhdhhtr1483967603-sonar.xz.fbcdn.net
157.240.21.32	A+PTR	edge-mqtt-mini-shv-01-cdt1.facebook.com
157.240.21.34	PTR	edge-sonar-mini-shv-01-cdt1.fbcdn.net
157.240.21.34	A	fe7b12d3680kdno4pyq-uyzgfbkv1498200125-sonar.xx.fbcdn.net
157.240.21.34	A	f65373a3080-oyxrjbqm1544777119-sonar.xz.fbcdn.net
157.240.21.35	A+PTR	edge-star-mini-shv-01-cdt1.facebook.com
157.240.21.36	A+PTR	edge-z-m-mini-shv-01-cdt1.facebook.com
157.240.21.36	A	z-m-scontent-cdt.xx.fbcdn.net
157.240.21.37	A+PTR	instagram-p15-shv-01-cdt1.fbcdn.net
157.240.21.37	A	edge-z-mini-shv-01-cdt1.facebook.com
157.240.21.37	A	z-p15-scontent-cdt1-1.cdninstagram.com
157.240.21.39	A+PTR	edge-star-z-mini-shv-01-cdt1.facebook.com
157.240.21.39	A	z-m-scontent-cdt.xx.fbcdn.net
157.240.21.39	A	z-m-fbcdn-mini-shv-01-cdt1.fbcdn.net
157.240.21.40	A+PTR	edge-snaptu-http-p2-shv-01-cdt1.facebook.com
157.240.21.41	A+PTR	edge-z-1-p2-shv-01-cdt1.facebook.com
157.240.21.48	A+PTR	edge-turnservice-shv-01-cdt1.facebook.com
157.240.21.50	A+PTR	edge-z-p3-shv-01-cdt1.facebook.com
157.240.21.50	A	z-p3-scontent-cdt1-1.xx.fbcdn.net
157.240.21.51	A+PTR	edgeray-shv-01-cdt1.facebook.com
157.240.21.52	A+PTR	whatsapp-cdn-shv-01-cdt1.fbcdn.net
157.240.21.52	A	w5f1720061kuv6jbea-gmzdcnrsga3tomju.snr.whatsapp.net
157.240.21.52	A	sonar-cdt.cdn.whatsapp.net
157.240.21.53	A+PTR	whatsapp-chatd-edge-shv-01-cdt1.facebook.com
157.240.21.63	A+PTR	instagram-p3-shv-01-cdt1.fbcdn.net
157.240.21.63	A	scontent-cdt1-1.cdninstagram.com
157.240.21.63	A	scontent-cdt.cdninstagram.com
157.240.21.172	A+PTR	instagram-p4-shv-01-cdt1.fbcdn.net
157.240.21.172	A	z-p4-scontent-cdt1-1.cdninstagram.com
157.240.21.174	A+PTR	instagram-p42-shv-01-cdt1.fbcdn.net
157.240.21.174	A	z-p42-scontent-cdt1-1.cdninstagram.com
157.240.21.197	A+PTR	fbcromwelledge-bgp-01-cdt1.facebook.com