Have you ever wondered what TCP port Exchange 2010/2013/2016 uses for database replication (log shipping and seeding)? That would be 64327 by default.
This can be checked using the Get-DatabaseAvailabilityGroup cmdlet:
Administrators can also change this default port is they so desire by using the Set-DatabaseAvailabilityGroup cmdlet with the -ReplicationPort parameter.
If you decide to do so, it is recommended to create a new Windows Firewall rule for the new port on all DAG members before the actual change to avoid any disruption to database replication. After the change, the existing firewall rule can then be deleted or updated (depending on the approach taken):