Software Secure Firewall Threat Defense
Platform Secure Firewall Threat Defense Virtual
Activity Onboard

Encrypted Traffic Handling Decryption Rules Troubleshoot Decryption Rules About TLS Heartbeat

Last updated: Jul 29, 2025

About TLS Heartbeat

Some applications use the TLS heartbeat extension to the Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS) protocols defined by RFC6520. TLS heartbeat provides a way to confirm the connection is still alive—either the client or server sends a specified number of bytes of data and requests the other party echo the response. If this is successful, encrypted data is sent.

When a managed device with TLS crypto acceleration enabled encounters a packet that uses the TLS heartbeat extension, the managed device takes the action specified by the setting for Decryption Errors in the decryption policy's Undecryptable Actions:

  • Block

  • Block with reset