Blocking iCloud Private Relay to Ensure Reliable DNS Filtering
Written by Owen Parry
Updated at January 30th, 2026
Table of Contents
What This Feature Is
Platform-Specific Behavior (DNS Filtering)
macOS
iOS / iPadOS
CyberFOX DNS Filtering Portal
Domains Blocked by CyberFOX
Recommended Settings for Apple Devices
Wi‑Fi Settings
iCloud+ Settings
Safari Settings
Mail App
Managing Private Relay via MDM
Advanced Use Cases
BYOD Environments
Compliance-Driven Networks
Mixed Apple / Non‑Apple Environments
Best Practices
Troubleshooting
Users See "/Private Relay Is Not Available on This Network/"
Websites Fail to Load on macOS/iOS
DNS Logs Show Continuous Relay Attempts
iCloud Login Behavior
Security & Sync Behavior
Additional References
CyberFOX DNS Filtering blocks Apple’s iCloud Private Relay by default to maintain accurate DNS policy enforcement, reliable traffic inspection, and full visibility across managed networks. Apple’s relay service encrypts DNS queries and obscures device IP addresses, which prevents CyberFOX from applying filtering rules, logging activity, or ensuring compliance. This article explains how the block works, its impact on Apple devices, recommended configuration settings, and how IT administrators can manage Private Relay through MDM platforms.
What This Feature Is
iCloud Private Relay is an Apple privacy service available on macOS and iOS that:
- Encrypts outbound DNS queries
- Routes traffic through Apple-managed relay servers
- Masks device IP addresses and network identifiers
Because traffic is tunneled through Apple’s relay infrastructure, DNS requests bypass CyberFOX DNS Filtering—making reliable categorization, policy enforcement, and security inspection impossible. To preserve network integrity, CyberFOX blocks DNS access to Apple’s Private Relay endpoints.
When Private Relay is enabled and not blocked:
- DNS filtering policies may be bypassed entirely
- Security and compliance visibility is lost
- Websites may fail to load or load partially due to mixed-resolution paths
- Reporting accuracy becomes fragmented across devices
Platform-Specific Behavior (DNS Filtering)
macOS
- Devices attempt to resolve relay domains automatically when Private Relay or related privacy features (e.g., Limit IP Tracking) are enabled.
- When CyberFOX blocks these domains, macOS displays system messages such as "Private Relay is not available on this network."
- DNS filtering continues normally for all non-relay traffic.
iOS / iPadOS
- iPhones and iPads attempt similar relay lookups.
- Users may see notifications in Wi‑Fi settings that Private Relay is disabled by the network.
- No user action is required—filtering will continue to function.
CyberFOX DNS Filtering Portal
- No special configuration is needed. Relay domains are blocked globally by default.
- Administrators may review or confirm the blocks under domain logs if required.
Domains Blocked by CyberFOX
CyberFOX prevents DNS resolution to all known Apple relay hosts to ensure DNS queries remain visible and enforceable:
- mask.icloud.com
- mask-h2.icloud.com
- mask-api.icloud.com
- mask.apple-dns.net
Blocking these domains ensures:
- Devices cannot establish the encrypted relay channel
- DNS traffic remains inside CyberFOX’s filtering infrastructure
- All activity continues to be logged, categorized, and enforced
Recommended Settings for Apple Devices
To reduce user confusion and eliminate unnecessary system warnings, CyberFOX recommends disabling the following privacy features on macOS and iOS:
Wi‑Fi Settings
- Limit IP Address Tracking → Off
iCloud+ Settings
- Private Relay → Off
Safari Settings
- Hide IP Address → Off
Mail App
- Mail Privacy Protection → Off
These features attempt to route DNS traffic through Apple’s relay, but CyberFOX will block it regardless.
Disabling them ensures:
- Fewer warning prompts to end users
- Clearer routing behavior
- More predictable DNS resolution
Managing Private Relay via MDM
Most Mobile Device Management (MDM) platforms provide configuration profiles to disable iCloud Private Relay across all managed Apple devices. This is the recommended enterprise‑grade approach.
Common MDM capabilities include:
- Enforcing Private Relay = Disabled (global)
- Restricting iCloud account modifications
- Restricting network privacy features
Platforms known to support this setting:
- Jamf Pro / Jamf School
- Intune (via device restrictions for Apple endpoints)
- Mosyle
- Kandji
- Addigy
IT administrators should follow their MDM vendor’s documentation for deployment. For Jamf specifically, Apple provides a clear configuration guide within the Jamf Community portal.
Advanced Use Cases
BYOD Environments
For Bring‑Your‑Own‑Device networks, CyberFOX still blocks relay endpoints, ensuring filtering is enforced regardless of device ownership. Administrators may pair this with a captive portal or onboarding instructions.
Compliance-Driven Networks
Organizations subject to CMMC, HIPAA, SOC2, PCI‑DSS, or similar frameworks must retain visibility into DNS activity. Blocking Private Relay ensures:
- Logging is complete
- DNS inspection is not circumvented
- Auditors receive accurate traffic data
Mixed Apple / Non‑Apple Environments
Private Relay attempts occur only on Apple devices, but blocking these domains has zero negative impact on Windows, Android, Linux, or IoT devices.
Best Practices
- Use MDM enforcement rather than user‑level instructions to ensure consistency.
- Document Private Relay restrictions in your company’s acceptable‑use or security onboarding materials.
- Regularly review DNS logs for unexpected relay attempts—spikes may indicate misconfigured profiles.
- Ensure Safari settings are aligned with organizational privacy and security requirements.
-
Test behavior on a macOS and iOS device after making profile changes.
Troubleshooting
Users See "/Private Relay Is Not Available on This Network/"
This is expected when CyberFOX blocks relay domains. Confirm the device is still applying DNS filtering normally.
Websites Fail to Load on macOS/iOS
- Ensure Private Relay, Limit IP Address Tracking, and Hide IP Address are disabled.
- Confirm the network is not using a secondary DNS resolver.
- Verify the device is not connected to a VPN that overrides DNS.
DNS Logs Show Continuous Relay Attempts
- Device likely has Private Relay enabled via user settings.
- Push an updated MDM profile to force-disable.
iCloud Login Behavior
Private Relay is unrelated to iCloud sync, App Store access, or Apple ID functionality. Blocking relay domains does not affect:
- Backups
- App downloads
- iCloud Drive
- Apple Mail
Security & Sync Behavior
CyberFOX blocks Private Relay specifically to preserve:
- Full DNS visibility
- Accurate categorization and policy enforcement
- Complete logging for audits
- Consistent behavior across managed networks
Apple’s relay does not synchronize with CyberFOX and does not share telemetry. DNS traffic routed through Private Relay cannot be inspected for:
- Malware domains
- Phishing indicators
- C2 activity
- Content‑filtering rules
Blocking the relay ensures synchronized and predictable filtering behavior for all Apple devices.
Additional References