Robtex

Up: 31.13.80.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 31.13.81.0/25
Down right: 31.13.81.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
31.13.81.1	PTR	edge-fblite-ws-p1-shv-01-waw1.facebook.com
31.13.81.1	A	wd66884.com
31.13.81.1	A	1381919.com
31.13.81.2	PTR	edge-m-shv-01-fra2.facebook.com
31.13.81.2	A	edge-atlas-shv-01-waw1.facebook.com
31.13.81.2	A	*.video-footjob.tumblr.com.cn
31.13.81.3	PTR	edge-mqtt-shv-01-fra2.facebook.com
31.13.81.3	A	edge-stun-shv-01-waw1.facebook.com
31.13.81.3	A	edge-cryptossl-shv-01-waw1.facebook.com
31.13.81.5	A+PTR	edge-mqtt-shv-01-waw1.facebook.com
31.13.81.6	PTR	edge-z-m-shv-01-fra2.facebook.com
31.13.81.6	A	edgetee-upload-waw.xx.fbcdn.net
31.13.81.6	A	livestream-edgetee-upload-shv-01-waw1.facebook.com
31.13.81.7	A+PTR	edge-snaptu-http-p1-shv-01-waw1.facebook.com
31.13.81.8	A+PTR	secure-edge-latest-shv-01-waw1.facebook.com
31.13.81.8	A	photos-b.xx.fbcdn.net
31.13.81.9	A+PTR	edge-star-shv-01-waw1.facebook.com
31.13.81.10	A+PTR	edge-video-shv-01-waw1.fbcdn.net
31.13.81.10	A	video-waw1-1.xx.fbcdn.net
31.13.81.10	A	video-waw.xx.fbcdn.net
31.13.81.11	A+PTR	edge-z-shv-01-waw1.facebook.com
31.13.81.11	A	ns1.ssv4.net
31.13.81.12	A	wwww.bodog888.com.wscy.cn
31.13.81.13	PTR	xx-fbcdn-shv-01-waw1.fbcdn.net
31.13.81.13	A	photos-b.xx.fbcdn.net
31.13.81.13	A	sonar-fgye.xx.fbcdn.net
31.13.81.15	A	www.yebar.net
31.13.81.15	A	edge-secure-shv-01-waw1.facebook.com
31.13.81.15	A	999123c.com
31.13.81.17	PTR	edge-extern-shv-01-waw1.facebook.com
31.13.81.17	A	tx8ff.com
31.13.81.17	A	vnsr919.com
31.13.81.18	PTR	edge-atlas-shv-02-fra2.facebook.com
31.13.81.18	A	optztwsj.com
31.13.81.18	A	edgetee-waw.xx.fbcdn.net
31.13.81.19	PTR	edge-mqtt-shv-02-fra2.facebook.com
31.13.81.19	A	cswsj.com
31.13.81.19	A	edge-z-p1-shv-01-waw1.facebook.com
31.13.81.21	A	edge-livestream-api-upload-shv-01-waw1.facebook.com
31.13.81.23	PTR	edge-resolver002-bgp-01-waw1.facebook.com
31.13.81.26	A	edge-shortwave-shv-01-waw1.facebook.com
31.13.81.32	A+PTR	instagram-p15-shv-01-waw1.fbcdn.net
31.13.81.32	A	xccp555.com
31.13.81.32	A	com--www.cracksitesluminarias77.com--www.szhsee.com
31.13.81.33	PTR	edge-star-shv-03-fra2.facebook.com
31.13.81.33	A	edge-snaptu-http-mini-shv-01-waw1.facebook.com
31.13.81.34	A+PTR	edge-mqtt-mini-shv-01-waw1.facebook.com
31.13.81.35	PTR	edge-sonar-mini-shv-01-waw1.fbcdn.net
31.13.81.35	A	fa89a3d9680-hgyauecn1550816634-sonar.xx.fbcdn.net
31.13.81.35	A	f1f6ecb9680knsvydii-ufscnhwi1517144737-sonar.xz.fbcdn.net
31.13.81.36	A+PTR	edge-star-mini-shv-01-waw1.facebook.com
31.13.81.37	A+PTR	edge-z-m-mini-shv-01-waw1.facebook.com
31.13.81.38	A+PTR	edge-fblite-tcp-mini-shv-01-waw1.facebook.com
31.13.81.38	A	edge-star-z-mini-shv-01-waw1.facebook.com
31.13.81.38	A	z-m-scontent-waw1-1.xx.fbcdn.net
31.13.81.41	A	stcywsj.com
31.13.81.41	A	edge-z-1-p2-shv-01-waw1.facebook.com
31.13.81.48	A+PTR	whatsapp-chatd-edge-shv-01-waw1.facebook.com
31.13.81.50	A+PTR	edgeray-shv-01-waw1.facebook.com
31.13.81.52	A+PTR	instagram-p3-shv-01-waw1.fbcdn.net
31.13.81.52	A	scontent-waw1-1.cdninstagram.com
31.13.81.52	A	scontent-b-waw.cdninstagram.com
31.13.81.53	A+PTR	whatsapp-cdn-shv-01-waw1.fbcdn.net
31.13.81.53	A	w638914471khydpind-gm4tknbshe3damzu.snr.whatsapp.net
31.13.81.53	A	w8122e7271kzkrnsyc-ge4tamrzg4ztkobs.snr.whatsapp.net
31.13.81.54	A+PTR	edge-z-p3-shv-01-waw1.facebook.com
31.13.81.54	A	z-p3-scontent-waw.xx.fbcdn.net
31.13.81.54	A	z-p3-scontent-waw1-1.xx.fbcdn.net
31.13.81.55	PTR	xx-fbcdn-shv-04-fra2.fbcdn.net
31.13.81.55	A	edge-turnservice-shv-01-waw1.facebook.com
31.13.81.57	PTR	edge-z-1-shv-04-fra2.facebook.com
31.13.81.66	PTR	edge-atlas-shv-05-fra2.facebook.com
31.13.81.81	PTR	edge-star-shv-06-fra2.facebook.com
31.13.81.97	PTR	edge-star-shv-07-fra2.facebook.com
31.13.81.103	PTR	xx-fbcdn-shv-07-fra2.fbcdn.net
31.13.81.128	PTR	edge-star-shv-09-fra2.facebook.com
31.13.81.133	PTR	edge-z-m-shv-09-fra2.facebook.com
31.13.81.172	A+PTR	instagram-p4-shv-01-waw1.fbcdn.net
31.13.81.172	A	z-p4-scontent-waw1-1.cdninstagram.com
31.13.81.174	A+PTR	instagram-p42-shv-01-waw1.fbcdn.net
31.13.81.174	A	z-p42-scontent-waw1-1.cdninstagram.com