Hi Phil,
Thank you for posting your query on Microsoft Q&A.
The issue you're experiencing is expected and relates to current IPv6 limitations in Microsoft Entra Global Secure Access (GSA). As of October 2025, GSA supports only IPv4 traffic, and any IPv6 connections bypass the GSA client, which can affect your Conditional Access policies and cause traffic to appear as “untrusted.”
Why You are Seeing This Behavior
1. IPv6 Not Supported by GSA: According to Microsoft’s official documentation, the Global Secure Access client tunnels only IPv4 traffic. IPv6 connections aren’t acquired or processed by the client, so they route directly through the network instead of the GSA tunnel. (Reference: Known Limitations for Global Secure Access)
2. Registry Settings Only Influence Protocol Preference: Your current registry setting
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters\DisabledComponents = 0x20
tells Windows to prefer IPv4 over IPv6, but it does not completely disable IPv6. The OS design mandates that IPv6 remains partially active to support key Windows and Entra services.
3. Conditional Access Policy Limitation with IPv6: If users’ devices initiate IPv6 connections, Conditional Access policies that rely on IP-based location evaluation may mark IPv6-based sessions as “unknown” or “non-trusted,” since they don’t traverse the GSA tunnel.
Recommended Steps to Fix or Work Around the Issue
1. Confirm Registry Setting and Reboot Ensure your registry value is correctly configured: HKLM\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters\DisabledComponents = 32 (hex 20)
Reboot the system to apply changes. This prioritizes IPv4 without disabling IPv6 entirely.
2. Disable Secure DNS and QUIC in Browsers Some browsers and applications use DNS over HTTPS (DoH), DNS over TLS (DoT), or QUIC—which prefer IPv6 for faster lookups—bypassing GSA. Disable QUIC and DoH in browsers like Microsoft Edge and Chrome to force IPv4 DNS traffic through the GSA client.
3. Use the “Compliant Network” Signal in Conditional Access Instead of enforcing IP-based location conditions, use Global Secure Access Compliant Network Check to evaluate if a session passes through the GSA tunnel. This approach is more robust and eliminates the need to maintain lists of trusted IPv4/IPv6 addresses. To enable this:
- In the Entra Admin Center, go to Global Secure Access > Settings > Session management > Adaptive access.
- Turn on Enable CA Signaling for Entra ID (covering all cloud apps).
- Verify that a named location called All Compliant Network locations exists. (Ref: Enable Compliant Network Check with Conditional Access)
4. Don’t Fully Disable IPv6 Microsoft explicitly discourages disabling IPv6 system‑wide. Some services (Entra ID, DNS, and internal name resolution) depend on IPv6 to function properly. Disabling it completely can lead to connectivity or authentication failures.
5. Monitor Known Limitations and Roadmap Updates IPv6 tunneling support is not yet available for the GSA client. Microsoft has indicated that enhancements including dual‑stack (IPv4 and IPv6) tunneling are under development. You can monitor upcoming updates here: Known Limitations for Global Secure Access
I hope this explanation clarifies the IPv6 behavior with Global Secure Access. Please click “Accept Answer” if this helps resolve your issue, and Upvote to assist others facing similar conditions.