In some environments, websites integrated with VergeCloud CDN may experience accessibility issues specifically on iOS devices such as iPhones and iPads. Users may encounter symptoms such as pages failing to load, blank screens, connection errors, or inconsistent website behavior.

A common workaround is to configure VergeCloud to ignore the Upgrade header through Page Rules. This prevents unnecessary protocol negotiation that may cause compatibility issues between iOS clients, the CDN, and the origin server.

When Should You Use This Configuration?

Consider applying this setting if:

• Your website loads normally on desktop browsers and Android devices but not on iOS devices.
• iPhone or iPad users report blank pages or connection failures.
• The issue appeared after enabling VergeCloud CDN.
• No application-level errors are visible on the origin server.

How to Configure the Setting

Step 1: Access Page Rules

Log in to the VergeCloud User Panel and navigate to:

Dashboard → Page Rules

Step 2: Edit the Relevant Rule

Locate the Page Rule associated with the affected website or URL pattern and click Edit Rule.

Step 3: Configure Ignored Headers

Within the Page Rule settings:

1. Locate the Ignore Sent Headers option.
2. Select Ignore Sent Headers from Origin Server.
   
3. Add the following header value:
   

Step 4: Save the Configuration

Save the rule and publish the changes.

Step 5: Repeat if Necessary

If multiple Page Rules are configured for the domain, repeat the process for any additional rules where the Upgradeheader should be ignored.

Why Ignoring the Upgrade Header Helps

The Upgrade HTTP header is typically used when a client or server wants to switch from the current protocol to another protocol.

Common examples include:

• HTTP to WebSocket upgrades
• Protocol negotiation between clients and servers
• Specialized real-time communication services

For standard website traffic, these protocol transitions are usually unnecessary. In certain cases, iOS devices may send, interpret, or expect Upgrade-related behavior differently from other browsers.

If the CDN edge server or origin application does not handle the header exactly as expected, the connection can fail, resulting in pages that do not load properly on iOS devices.

By instructing VergeCloud to ignore the Upgrade header, requests continue using the normal HTTP/HTTPS workflow without attempting an unnecessary protocol transition.

Common Causes of iOS Compatibility Issues

Unnecessary Protocol Negotiation

Some iOS browsers or applications may initiate protocol upgrade behavior even when the website does not require it.

Ignoring the Upgrade header ensures requests remain on the standard HTTPS connection, eliminating unnecessary negotiation steps.

Browser-Specific Behavior

Different browsers interpret HTTP headers differently.

While Chrome, Firefox, or Android browsers may handle a particular response without issue, Safari on iOS can sometimes react differently when Upgrade-related headers are present, leading to page rendering or connection failures.

CDN and Edge Processing Conflicts

If an Upgrade request reaches a CDN edge node that is not configured to support the requested protocol on that specific path, the request may not be processed as expected.

Ignoring the header removes this ambiguity and allows requests to follow the normal delivery path.

Cache Consistency

Protocol upgrade requests can occasionally interfere with standard caching behavior.

Removing unnecessary Upgrade processing helps ensure that requests are handled consistently across all edge locations and devices.

Improved Cross-Platform Compatibility

Ignoring the Upgrade header simplifies HTTP communication and reduces the likelihood of browser-specific compatibility issues, resulting in a more predictable experience across desktop and mobile platforms.

Expected Result

After configuring VergeCloud to ignore the Upgrade header:

• iPhone and iPad users should be able to access the website normally.
• Standard HTTPS communication remains unaffected.
• Unnecessary protocol upgrade attempts are prevented.
• Page rendering and connectivity issues related to iOS compatibility are typically resolved.
• Website behavior becomes more consistent across browsers and devices.

Notes

• This setting should only be applied when Upgrade-header-related compatibility issues are suspected or confirmed.
• If your application actively uses WebSockets or other protocol upgrade mechanisms, test carefully before applying this change globally.
• After making the change, clear browser cache on the affected device and retest the website to verify that the issue has been resolved.

By configuring VergeCloud to ignore the Upgrade header when appropriate, administrators can quickly resolve a class of iOS-specific accessibility issues while maintaining stable and reliable content delivery through the CDN.