You can customize a Web server domain name that a CDN node accesses in the back-to-source process.
Notice: The Back-to-source host must be set to the CDN domain for data to return to the source because an origin site is a CDN domain in the OSS space.
Log on to the CDN console.
On the left-side navigation pane, click Domain Names.
Select a domain to enter the management page.
Set Back-to-source Host.
The Back-to-source Host configuration is optional and its default value is CDN Domain.
The value options include CDN Domain, original site domain name, and Custom domain name.