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MC1189910: Configure Local Network Access Policy for Microsoft eCDN

By: Author Alex Lim

Posted on

Categories Update

Home » Update » MC1189910: Configure Local Network Access Policy for Microsoft eCDN

Summary

  • Changes to Microsoft eCDN configuration due to Chrome 142 enforcing Local Network Access restrictions impacting peer-to-peer functionality.
  • Admins need to configure the LocalNetworkAccessAllowedForUrls policy by adding specific URLs for optimal performance in Teams Live Events and Town Halls.
  • Settings can be applied via Group Policy or registry keys for Microsoft Edge and Google Chrome.
  • US Government tenants should use GCC/GCC High-specific hostnames as per documentation.
  • This change aligns with Microsoft’s Unified Domains initiative, requiring attention to both legacy and new domains.

Admin Impact: High
User Impact: Low
Release Start: 26 Nov 2025
Release End: 26 Nov 2025
Services: M365, M365 Apps
Category: Plan for change
Tags: User Adoption, Admin Action

History

11/25/2025 Item Added to Message Center

Microsoft Message

We’re making some changes to the Microsoft eCDN configuration.

Starting with Chrome 142, browsers will enforce Local Network Access restrictions that may impact Microsoft eCDN peer-to-peer functionality.

How this will affect your organization

You are receiving this message because our reporting indicates one or more users in your organization may be using this Microsoft eCDN. To maintain optimal performance for Teams Live Events and Town Halls, admins must configure the LocalNetworkAccessAllowedForUrls policy for Chrome-based browsers

What you need to do to prepare

Admins will need to:

Add the following URLs to the LocalNetworkAccessAllowedForUrls policy in your environment:

*.
ecdn.teams.microsoft.com
https://teams.microsoft.com
*.
ecdn.teams.cloud.microsoft
https://teams.cloud.microsoft
https://engage.cloud.microsoft/

Apply these settings via Group Policy or registry keys for:

  • Microsoft Edge: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Edge\
  • Google Chrome: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome\

For US Government tenants, use GCC/GCC High-specific hostnames as outlined in the documentation.

Additional Notes:

  • This change aligns with Microsoft’s Unified Domains initiative. Ensure your network filters include both legacy and new domains.
  • Pair this configuration with WebRtcLocalIpsAllowedUrls for full peer-to-peer functionality.
  • Firefox restrictions are planned but not yet enforced.

See documentation for full guidance: Configure Local Network Access Policy for Microsoft eCDN