Cisco: Security - Clustering a Firepower 4100 with FTD 6.3
Channel: Nathan Stapp
Date: 27/02/2019

Cisco Security Consultant Sales Engineer (CSE) here...
This is a video that documents the entire process from start to finish of clustering:
Firepower 4100 chassis (identical across chassis)
FTD 6.3 code (unique to code base)