Ignore "upgrade" Header

If your website becomes inaccessible to iOS users (e.g., on iPhones or iPads) after integrating VergeCloud CDN, you can resolve the issue by adjusting the Page Rules in your VergeCloud User Panel. Follow the steps below:

1. Access Page Rules: Go to the VergeCloud User Panel and navigate to the Page Rules section.
2. Edit Rule: Click on "Edit Rule" for the relevant page rule(s).
3. Ignore Sent Headers: Select the option to "Ignore sent Headers" from the main server.
4. Enter "Upgrade": In the field provided, add the word Upgrade to ensure these headers are ignored.
5. Apply Changes to All Relevant Rules: Repeat this step for all rules in the Page Rules section where you wish to ignore the Upgrade header.

Why Ignoring the "Upgrade" Header Resolves iOS Accessibility Issues

When your website is served through VergeCloud’s CDN, the Upgrade header typically allows or signals a switch to another protocol (e.g., WebSockets). However, some iOS devices (iPhones or iPads) can send this header (or encounter it in a response) in scenarios where no protocol switch is actually needed. If VergeCloud or your origin server does not handle the Upgrade header the way iOS expects, it can lead to connection failures or blank pages on iOS devices.

By ignoring the Upgrade header in VergeCloud’s Page Rules, you effectively disable the protocol-switch attempt for standard HTTP/HTTPS requests that do not truly require a protocol upgrade. This prevents iOS from attempting a switch that is unneeded or unsupported in the current context, thereby eliminating the conflict that renders the page inaccessible.

Key Reasons to Ignore the Upgrade Header for iOS

• Unnecessary Protocol Switches: iOS Safari or apps might initiate or expect a protocol switch (e.g., HTTP to WebSocket) when it’s not actually needed. Ignoring the Upgrade header ensures the connection remains on the standard protocol without interruption.
• Browser-Specific Handling: Different browsers handle headers differently. iOS Safari may be stricter or behave unexpectedly if the server responds in a way that conflicts with the Upgrade header, causing the page to fail to load.
• Edge Cache Conflicts: If your CDN edge server receives Upgrade but isn’t configured to support it on the specific path, it might disrupt caching or cause requests to fail. Ignoring the header for normal web traffic avoids these cache misalignments.
• Simplified HTTP Requests: Removing or ignoring an unneeded Upgrade header keeps HTTP transactions straightforward and consistent across all devices, reducing the risk of device-specific quirks or compatibility issues.

Practical Effect

Once you configure VergeCloud to ignore the Upgrade header for the affected URL paths, iOS devices no longer attempt an unsupported protocol transition on those paths. As a result, your website remains accessible and renders correctly for iPhone or iPad users.