This article is intended for network administrators.
How Apple Push Notification Service connects
To use Apple Push Notification Service (APNs), your macOS and iOS clients need a direct and persistent connection to Apple's servers.
Your iPhone, iPad, or iPod touch might connect to APNs over cellular data (if capable) or Wi-Fi.
Check required ports
If you use Wi-Fi behind a firewall, or private Access Point Name for cellular data, connect to specific ports. You need a direct, unproxied connection to the APNs servers on these ports:
- TCP port 5223 to communicate with APNs.
- TCP port 443 or 2197 to send notifications to APNs.*
- TCP port 443 is required during device activation, and afterwards for fallback (on Wi-Fi only) if devices can't reach APNs on port 5223.
The APNs servers use load balancing, so your devices don't always connect to the same public IP address for notifications. It's best to let your device access these ports on the entire 18.104.22.168/8 address block, which is assigned to Apple.