![](https://secondadvisories.com/wp-content/uploads/2019/01/2019.01.05a-IMG_0863-Custom-1024x768.jpg)
Heartbeat is required in resilience configuration such that primary and secondary devices are constantly communicating.
A question for the reader: if somehow they can’t communicate, how does the infrastructure know if:
- The link fails, or
- The counterpart is down