Sync and cloud storage

*.cdn-apple.com

Hosts under cdn-apple.com are Apple's content delivery. Apple lists the whole domain for iCloud services, and several hosts under it for other jobs.

Run by ApplePorts: 443 TCPChecked: 1 November 2026

Short answer

An Apple content delivery domain. Apple lists it for iCloud services; update and sign-in hosts sit under it too.

Don’t block

Don't block the whole domain. iCloud, software updates and Apple Account sign-in use hosts under it.

Matches
*.cdn-apple.com

A name with *. covers every name under it: *.push.apple.com matches 1-courier.push.apple.com.

What it serves

Apple's enterprise host list names *.cdn-apple.com in its iCloud section, for iCloud services.

Hosts under it with their own entries: updates.cdn-apple.com for software update downloads, account.apple.com for Apple Account sign-in and app-site-association.cdn-apple.com for universal links.

Apple also lists fcs-keys-pub-prod.cdn-apple.com and idv.cdn-apple.com for other features. Kilobat matches the most specific entry first.

Processes that use it

clouddPart of macOS. It syncs the iCloud data of apps that use CloudKit, so its traffic belongs to those apps.Process →softwareupdatedPart of macOS. It checks for and downloads macOS updates, security responses and system files.Process →

What breaks if you block it

Don’t block

Don't block the whole domain. iCloud, software updates and Apple Account sign-in use hosts under it.

What breaks if you block it

  • iCloud services may fail.
  • Software update downloads from updates.cdn-apple.com fail.
  • Apple Account sign-in in System Settings may fail.

With Kilobat Pro and the network filter, you can block a host for every app or for one app: in Connections, select a connection and choose Block. Apple’s own services are never blocked by Kilobat’s Protection lists.

Apple’s rules for its hosts

Apple’s list, Use Apple products on enterprise networks, says that devices open these connections, not Apple’s servers. Apple services fail any connection that uses HTTPS interception, so a proxy that inspects TLS should leave Apple’s hosts alone.

If a firewall allows hosts by name, allowing *.apple.com covers most Apple services, Apple says. A firewall that works only with addresses can allow 17.0.0.0/8 for IPv4, and 2403:300::/32, 2620:149::/32 and 2a01:b740::/32 for IPv6.

To see which app on your Mac opened a connection to this host, use Kilobat’s Connections tab, or the agent network log for AI agents.

Sources

Checked on 1 November 2026.