> ## Documentation Index > Fetch the complete documentation index at: https://gcore-doc-1256a.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Specify TLS versions allowed for content requests from the CDN The option specifies a list of allowed SSL/TLS protocol versions. The list cannot be empty. By default, the option is disabled, and all the protocol versions are allowed. Possible values (case sensitive): * SSLv3 * TLSv1 * TLSv1.1 * TLSv1.2 * TLSv1.3 To manage TLS versions option: 1\. In the Gcore Customer Portal, navigate to **CDN**. You'll be directed to the **CDN resources** page. 2\. Find the needed resource and click on its CNAME to open the settings. CDN resources page with a resource CNAME highlighted 3\. Scroll down to the **TLS versions** section and click the **Change TLS versions** toggle to specify the necessary versions. The other versions you haven't specified will be blocked. TLS versions in resource settings