Robtex

Up: 54.192.20.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 54.192.20.0/25
Down right: 54.192.20.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
54.192.20.8	PTR	server-54-192-20-8.hkg62.r.cloudfront.net
54.192.20.8	A	server-54-192-20-8.ewr2.r.cloudfront.net
54.192.20.9	PTR	server-54-192-20-9.hkg62.r.cloudfront.net
54.192.20.9	A	server-54-192-20-9.ewr2.r.cloudfront.net
54.192.20.9	A	d1u2cbczpt82kt.ewr2.cloudfront.net
54.192.20.13	A	d1u2cbczpt82kt.ewr2.cloudfront.net
54.192.20.33	A+PTR	server-54-192-20-33.ewr2.r.cloudfront.net
54.192.20.44	A+PTR	server-54-192-20-44.ewr2.r.cloudfront.net
54.192.20.46	PTR	server-54-192-20-46.hkg62.r.cloudfront.net
54.192.20.46	A	server-54-192-20-46.ewr2.r.cloudfront.net
54.192.20.52	A+PTR	server-54-192-20-52.ewr2.r.cloudfront.net
54.192.20.63	PTR	server-54-192-20-63.hkg62.r.cloudfront.net
54.192.20.63	A	server-54-192-20-63.ewr2.r.cloudfront.net
54.192.20.101	PTR	server-54-192-20-101.hkg62.r.cloudfront.net
54.192.20.101	A	server-54-192-20-101.ewr2.r.cloudfront.net
54.192.20.123	A+PTR	server-54-192-20-123.ewr2.r.cloudfront.net
54.192.20.167	A+PTR	server-54-192-20-167.ewr2.r.cloudfront.net
54.192.20.168	PTR	server-54-192-20-168.ewr2.r.cloudfront.net
54.192.20.169	PTR	server-54-192-20-169.dfw54.r.cloudfront.net
54.192.20.169	A	d1u2cbczpt82kt.ewr2.cloudfront.net
54.192.20.169	A	ads.a.playnomics.net
54.192.20.236	PTR	server-54-192-20-236.hkg62.r.cloudfront.net
54.192.20.236	A	server-54-192-20-236.ewr2.r.cloudfront.net
54.192.20.243	A+PTR	server-54-192-20-243.ewr2.r.cloudfront.net
54.192.20.243	A	d1u2cbczpt82kt.ewr2.cloudfront.net
54.192.20.243	A	ads.a.playnomics.net