Robtex

Up: 17.57.152.0/22
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Down left: 17.57.154.0/24
Down right: 17.57.155.0/24

IP	Type	Hostname
17.57.154.4	A+PTR	ic4-privaterelay.appleid.com
17.57.154.4	A+PTR	smtp2.ic4-privaterelay.appleid.com
17.57.154.5	A+PTR	smtp2.ic1-privaterelay.appleid.com
17.57.154.5	A+PTR	ic1-privaterelay.appleid.com
17.57.154.6	PTR	mx01.mail.icloud.com
17.57.154.7	A+PTR	mx02.mail.icloud.com
17.57.154.8	A	p33-mailws.icloud.com.akadns.net
17.57.154.16	A+PTR	privaterelay.appleid.com
17.57.154.16	A+PTR	smtp2.privaterelay.appleid.com
17.57.154.23	A+PTR	mx01.mail.icloud.com