MC1066155 – Microsoft SharePoint Online: [Important update] Enabling a new Public Content Delivery Network (CDN) domain (archived)

Product:

SharePoint

Platform:

Online, US Instances, Web, World tenant

Status:

Launched

Change type:

Admin impact

Links:

489230

Details:

Summary:
Microsoft SharePoint Online will migrate to a new CDN service, Microsoft Azure Front Door, starting June 2025 and completing by July 2025. Organizations should add the new domain `public-cdn.sharepointonline.com` to their allow list, avoid hardcoding CDN URLs, and continue allowing the old domain. No admin action is required before the rollout.

Details:
Coming soon: We will migrate the hosting of Microsoft SharePoint Online assets to a new content delivery network (CDN) service, Microsoft Azure Front Door (AFD).
This message is associated with Microsoft 365 Roadmap ID 489230.
[When this will happen:]
General Availability (Worldwide): We will begin rolling out early June 2025 and expect to complete by late July 2025.

Change Category:
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Scope:
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Release Phase:
General Availability

Created:
2025-05-02

updated:
2025-05-02

Task Type

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Docu to Check

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MS How does it affect me

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MS Preperations

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MS Urgency

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linked item details

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summary for non-techies**

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Direct effects for Operations**

CDN Domain Allow Listing
Failure to add the new CDN domain to the allow list may result in users being unable to access SharePoint Online assets, leading to disruptions in service.
   - roles: IT Administrator, End User
   - references: https://learn.microsoft.com/microsoft-365/enterprise/use-microsoft-365-cdn-with-spo?view=o365-worldwide, https://www.microsoft.com/microsoft-365/roadmap?filters=&searchterms=489230

Hardcoding CDN URLs
If organizations have hardcoded the old CDN URLs, they may experience broken links or missing assets, negatively impacting user experience and productivity.
   - roles: Developer, End User
   - references: https://learn.microsoft.com/microsoft-365/enterprise/use-microsoft-365-cdn-with-spo?view=o365-worldwide, https://www.microsoft.com/microsoft-365/roadmap?filters=&searchterms=489230

Old Domain Blocking
Blocking the old CDN domain could lead to service interruptions as users may still rely on it for accessing SharePoint Online content.
   - roles: IT Administrator, End User
   - references: https://learn.microsoft.com/microsoft-365/enterprise/use-microsoft-365-cdn-with-spo?view=o365-worldwide, https://www.microsoft.com/microsoft-365/roadmap?filters=&searchterms=489230

Performance Issues
Without proper preparation, users may experience slower load times or performance degradation during the transition to the new CDN, affecting overall user satisfaction.
   - roles: End User, IT Support
   - references: https://learn.microsoft.com/microsoft-365/enterprise/use-microsoft-365-cdn-with-spo?view=o365-worldwide, https://www.microsoft.com/microsoft-365/roadmap?filters=&searchterms=489230

Configuration Review
Neglecting to review current configurations may lead to unforeseen issues post-migration, resulting in additional support requests and user frustration.
   - roles: IT Administrator, Project Manager
   - references: https://learn.microsoft.com/microsoft-365/enterprise/use-microsoft-365-cdn-with-spo?view=o365-worldwide, https://www.microsoft.com/microsoft-365/roadmap?filters=&searchterms=489230

Configutation Options**

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Opportunities**

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Potentional Risks**

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IT Security**

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explanation for non-techies**

Microsoft SharePoint Online is making a change to how it delivers content to users. Imagine SharePoint as a library that provides digital books and resources to people all over the world. To make sure everyone gets their digital books quickly, SharePoint uses a network of delivery trucks (called a Content Delivery Network or CDN) that distribute these resources from various locations.

Currently, SharePoint uses a specific fleet of trucks, but starting in June 2025, it will switch to a new fleet provided by Microsoft Azure Front Door. This new fleet will have a new identifier, like a new logo on the trucks, which is the domain name `public-cdn.sharepointonline.com`. To ensure these trucks can deliver to your office, you need to let your security team know to allow this new logo through your building's security gates (network allow list).

It's important not to write down the truck's old logo (the old CDN domain) in permanent ink on your office's delivery instructions (avoid hardcoding CDN URLs). This way, if the logo changes again in the future, you won't have to rewrite everything. Also, don't stop the old trucks just yet; they still have deliveries to make until you get a notice saying otherwise.

No immediate action is needed from your side before this change, as the transition will happen automatically. However, it’s a good idea to review your current setup to see how this change might affect your organization. If you have any questions or need help, you can reach out to Microsoft's support team. This update aims to improve the speed and reliability of accessing SharePoint Online resources, much like upgrading to a faster and more efficient delivery service for your digital library.