Hi Binoj,
There is no protocol or port on which the replication takes place between the two firewalls. For unit health check, hello packets are exchange between the two firewalls through failover interfaces, you can just apply captures on these failover interfaces and verify the protocol for these hello packets, I guess it uses protocol 105 for it. Any specific issue why you need this info??
Hope this helps.
Varun
Thanks,
Varun Rao