Robtex

Up: 13.33.36.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 13.33.36.0/25
Down right: 13.33.36.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
13.33.36.40	PTR	server-13-33-36-40.bos50.r.cloudfront.net
13.33.36.40	A	smabruderan-prj.slack.com
13.33.36.40	A	vivosqm.slack.com
13.33.36.152	PTR	server-13-33-36-152.sin2.r.cloudfront.net
13.33.36.152	A	server-13-33-36-152.bos50.r.cloudfront.net
13.33.36.179	A+PTR	server-13-33-36-179.bos50.r.cloudfront.net
13.33.36.181	A+PTR	server-13-33-36-181.bos50.r.cloudfront.net