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Select TLS protocol versions

TLS (Transport Layer Security) is a cryptographic protocol that provides secure data transmission between a CDN server and a user's browser.

By default, a CDN resource supports all TLS protocol versions, as well as SSLv3 for browser compatibility. Not all supported protocols meet security standards: TLSv1, TLSv1.1, and SSLv3 are considered obsolete. The use of modern protocols can be important, for example, if a service processes payments—it must comply with the PCI DSS standard, which requires the use of only modern TLS versions 1.2 and 1.3.

To improve the security of a TLS connection, you can use modern versions of the TLS protocol or select specific versions that the CDN resource will support. When using modern TLS versions, you can also enable SSL encryption for additional protection.

To select TLS protocol versions:

  1. In the Control panel, in the top menu, click Products and select CDN.

  2. Under CDN resources, open the resource page → General tab.

  3. Select which TLS protocol versions the CDN resource will support:

    • modern TLS versions — select the Use only modern TLS versions checkbox. The connection will be established via TLSv1.2 and TLSv1.3; other protocol versions will be disabled;

    • specific TLS versions — in the TLS protocols field, select the required versions.

  4. Optional: if you selected the Use only modern TLS versions checkbox in step 3, select the Use strong SSL ciphers checkbox. SSL encryption additionally enhances the security of the TLS connection.

  5. Click Apply. While the settings are being applied, the CDN resource will be in the PROCESSING status. During this time, applying other settings is unavailable. The settings will be applied once the CDN resource switches to the ACTIVE status.