Unable to establish a connection to the SQL server (error 80020009)

Products

• Endpoint Threat Defense for Active Directory

Issue/Introduction

You want to use a dedicated sql server, however, you are unable to establish a connection to the SQL server.

You get "Error 80020009" when testing the connection. 

Environment

TLS 1.2 enabled on SQL server

Cause

TDAD (Symantec Endpoint Threat Defense for Active Directory) version 3.6 and below do not support connection to SQL using TLS 1.2

Resolution

To have TLS 1.2 compatibility, please upgrade TDAD to version 3.6.2.2