About macOS, iOS, and iTunes server host connections and iTunes background processes

Some Apple software, including macOS, iOS, and iTunes, uses different ports and servers to connect to various services. iTunes for Windows also installs some processes that run in the background when the software is open.

Make sure that your security software is set up correctly. Setup steps vary by software, so contact the developer for specifics.

On Mac, applications signed by Apple automatically receive incoming connections. This article doesn't apply if you're using the macOS built-in Application Firewall.

Server connections

The following servers are used by macOS, iOS, and iTunes:

Apple servers Other servers
albert.apple.com evintl-ocsp.verisign.com
appldnld.apple.com evsecure-ocsp.verisign.com
configuration.apple.com *.amazonaws.com
*.cdn-apple.com *.digicert.com
deimos3.apple.com *.symcb.com
gg*.apple.com *.symcd.com

Common ports

The following ports are used or relied on by Apple software, including macOS, iOS, and iTunes:

Ports TCP or UDP Used by
80 TCP World Wide Web and services, iCloud, QuickTime Installer, iTunes Store and Radio, AirPlay
443 TCP TLS websites and services, iTunes Store, iCloud authentication and DAV services
123 TCP/UDP Network Time Protocol (NTP) used for network time server synchronization, AppleTV Network Time Server Sync
554 TCP/UDP Streaming media players, AirPlay
1900 TCP Bonjour Service
3689 TCP DAAP, iTunes Music Sharing, AirPlay
5223 TCP iCloud DAV Services (Contact, Calendars, and Bookmarks), Photo Stream
5224 TCP Spotlight Suggestions
5350 (UDP) UDP Bonjour Service
5351 (UDP) UDP Bonjour Service
5353 (UDP) UDP Bonjour, AirPlay, and Home Sharing Services
8000-8999 TCP Web service, Internet Radio streams
42000-42999 TCP Internet Radio streams

Learn more about TCP and UDP ports used by Apple software products. Blocked ports are often related to errors numbered in the 3000 range.

iTunes for Windows processes

iTunes for Windows installs some processes that run in the background when the software is open. Learn more about what each process does:

Process What it does
AppleMobileBackup.exe Backs up the data on your iPhone or iPod touch
AppleMobileDeviceHelper.exe Listens for commands to help iTunes communicate with devices
AppleMobileDeviceService.exe Allows iTunes to recognize iPhone and iPod touch
AppleMobileSync.exe Synchronizes iPhone or iPod touch data with your computer
distnoted.exe Allows iTunes to sync with iPhone and iPod touch
iPodService.exe Allows iTunes to access devices
iTunesHelper.exe Listens for commands to help iTunes communicate with devices (such as iPod)
iTunesPhotoProcessor.exe Transcodes photos and artwork for devices
MDCrashReportTool.exe Extracts log reports from the device and submits them to Apple (if selected)
mDNSResponder.exe This lets iTunes discover services on the local network (music sharing, Apple TV, AirTunes). It's also known as Bonjour for Windows.
SyncServer.exe Coordinates the synchronization processes
qttask.exe This provides a QuickTime icon in the Notification area (system tray) of the Windows Task bar. This process might or might not appear, depending on your QuickTime setup and if the QuickTime icon is enabled in the Notification area.
Process that depends on Sync configuration What it does
dotmacsyncclient.exe Syncs the device with iCloud
com.google.ContactSync.exe Google contact syncing
com.apple.IE.client.exe Syncs the device with Internet Explorer
com.apple.Outlook.client.exe Syncs the device with Outlook
com.apple.Safari.client.exe Syncs the device with Safari
com.apple.WindowsContacts.client.exe Syncs the device with Windows Address Book / Windows Contacts
com.apple.WindowsMail.client.exe Syncs with Windows Mail
com.yahoo.go.sync.client.exe Syncs with Yahoo

Depending on your setup, some of these background processes might not appear. iTunes can start other background processes to perform various tasks like syncing and diagnostics. New functions might be added to these background processes in the future. You shouldn't disable these processes even when iTunes isn't open on the computer.

Information about products not manufactured by Apple, or independent websites not controlled or tested by Apple, is provided without recommendation or endorsement. Apple assumes no responsibility with regard to the selection, performance, or use of third-party websites or products. Apple makes no representations regarding third-party website accuracy or reliability. Contact the vendor for additional information.

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