What does this error mean?

This error means the SSL/TLS handshake between two nodes was unsuccessful within the configured timeout window.

Why does this error occur?

An SSL handshake, in one-way or two-way communication, can fail for multiple reasons. The most common reasons are as follows:

• Missing Server Certificate
• Untrusted Server Certificate
• Missing Client Certificate
• Incorrect Certificates
• Incompatible SSL Version
• Incompatible Cipher Suite
• Network latency

How do you fix this error?

Verify that the SSL/TLS certificates are in-place and valid. Additionally, verify that the cipher suite in use is the same on both ends of the handshake. Finally, check your network connection between the two nodes to rule out any network related causes. For further help, DataStax Support can assist.