The Monitoring Console can do that for you.
There are a number of events you can use as a heartbeat. Search the internal index for one your forwarder's names to find them.
Used this to find the HF's
| set diff [search earliest="-30m" index=_internal host="*-splunk-hf"
| dedup host
| table host] [search earliest="-10m" index=_internal host="*-splunk-hf"
| dedup host
| table host]
The Monitoring Console can do that for you.
There are a number of events you can use as a heartbeat. Search the internal index for one your forwarder's names to find them.