Robtex

Up: 17.56.0.0/19
Can't show all results, try to descend to a more specific CIDR
Down left: 17.56.0.0/21
Down right: 17.56.8.0/21
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
17.56.0.23	A	p65-contentws.be.apple-dns.net
17.56.0.23	A	aodc.cws.v.aaplimg.com
17.56.0.85	A	aodc.cws.v.aaplimg.com
17.56.0.103	A	p67-iwmb.be.apple-dns.net
17.56.0.104	A	p67-iworkexportws.be.apple-dns.net
17.56.0.105	A	p67-iworkthumbnailws.be.apple-dns.net
17.56.0.107	A	p67-iwres.be.apple-dns.net
17.56.1.20	A	p69-iwmb.be.apple-dns.net
17.56.8.7	A	p65-smtp.mail.me.com.akadns.net
17.56.8.8	A	p65-mailws.icloud.com.akadns.net
17.56.8.68	A	p67-smtp.mail.me.com.akadns.net
17.56.8.70	A	p67-imap.mail.me.com.akadns.net
17.56.8.72	A	p67-mailws.icloud.com.akadns.net
17.56.8.104	A	p69-mailws.icloud.com.akadns.net
17.56.8.133	A	imap.mail.me.com.akadns.net
17.56.9.4	A	p98-mailws.icloud.com.akadns.net
17.56.9.16	PTR	smtp3.privaterelay.appleid.com
17.56.9.16	A+PTR	privaterelay.appleid.com
17.56.9.17	A+PTR	mx01.mail.icloud.com
17.56.9.19	A+PTR	mx02.mail.icloud.com
17.56.10.6	A+PTR	origin-itunesconnect-pv.apple.com
17.56.10.18	PTR	keychest-service-locker-synchronizer-uat.itunes.apple.com
17.56.10.18	PTR	spreview-pv.itunes.apple.com
17.56.10.18	PTR	daiquiri-amp-all-shared-ext-001-pv.itunes.apple.com