Symptom:
If a switch is online long enough to process 1 billion AOM updates, the "FFM" process may crash. Eg:

  hap_sup_reset: Reason Code:[2] Reset Reason:Service [ffm] pid:[4586] terminated abnormally [6].

"AOM" (Asynchronous Object Manager) is a mechanism often used for delivering programming updates between software processes that have a role in packet forwarding operations. "FFM" (Forwarding and Feature Manager) is an example of one such process that can handle AOM objects.

Conditions:
The issue happens when a software counter goes beyond about 1 billion (2^30) hitting the limit of what its datatype can handle.

The issue is often seen with multicast updates triggering AOM objects to update. 

The rate at which this issue can be encountered is highly dependent on the network and how often AOM updates need to happen internally. However, generally speaking, this issue can be encountered in several months of years of uptime.