Robtex

Up: 54.192.4.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 54.192.5.0/25
Down right: 54.192.5.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
54.192.5.4	A+PTR	server-54-192-5-4.dfw3.r.cloudfront.net
54.192.5.20	PTR	server-54-192-5-20.dfw3.r.cloudfront.net
54.192.5.23	A+PTR	server-54-192-5-23.dfw3.r.cloudfront.net
54.192.5.27	PTR	server-54-192-5-27.gru1.r.cloudfront.net
54.192.5.35	A+PTR	server-54-192-5-35.dfw3.r.cloudfront.net
54.192.5.37	PTR	server-54-192-5-37.dfw3.r.cloudfront.net
54.192.5.45	PTR	server-54-192-5-45.gru1.r.cloudfront.net
54.192.5.61	A+PTR	server-54-192-5-61.dfw3.r.cloudfront.net
54.192.5.64	A+PTR	server-54-192-5-64.dfw3.r.cloudfront.net
54.192.5.85	A+PTR	server-54-192-5-85.dfw3.r.cloudfront.net
54.192.5.96	A+PTR	server-54-192-5-96.dfw3.r.cloudfront.net
54.192.5.109	A+PTR	server-54-192-5-109.dfw3.r.cloudfront.net
54.192.5.110	PTR	server-54-192-5-110.dfw3.r.cloudfront.net
54.192.5.112	PTR	server-54-192-5-112.dfw3.r.cloudfront.net
54.192.5.113	PTR	server-54-192-5-113.dfw3.r.cloudfront.net
54.192.5.141	A+PTR	server-54-192-5-141.dfw3.r.cloudfront.net
54.192.5.158	PTR	server-54-192-5-158.dfw3.r.cloudfront.net
54.192.5.160	A+PTR	server-54-192-5-160.dfw3.r.cloudfront.net
54.192.5.165	A+PTR	server-54-192-5-165.dfw3.r.cloudfront.net
54.192.5.173	PTR	server-54-192-5-173.dfw3.r.cloudfront.net
54.192.5.173	A	wagone.slack.com
54.192.5.173	A	centralmagicjudges.slack.com
54.192.5.189	A+PTR	server-54-192-5-189.dfw3.r.cloudfront.net
54.192.5.190	A+PTR	server-54-192-5-190.dfw3.r.cloudfront.net
54.192.5.190	A	irc.slack.com
54.192.5.213	PTR	server-54-192-5-213.gru1.r.cloudfront.net
54.192.5.213	A	esbhollandcasino.slack.com
54.192.5.213	A	smreviewerspace.slack.com
54.192.5.214	A+PTR	server-54-192-5-214.dfw3.r.cloudfront.net
54.192.5.214	A	ed-sec.smugmug.com
54.192.5.228	A+PTR	server-54-192-5-228.dfw3.r.cloudfront.net
54.192.5.229	A	pikstudios.smugmug.com
54.192.5.238	A+PTR	server-54-192-5-238.dfw3.r.cloudfront.net