Hyper-V Replica starts network listeners for replication. These require firewall rules to be enabled for the ports that are ...

Hyper-V Replica starts network listeners for replication. These require firewall rules to be enabled for the ports that are assigned to Hyper-V Replica. Windows Firewall rules are not enabled on some of the servers.  Replication for virtual machines that are on those servers will stop. Ensure that the firewall rules for Hyper-V Replica are enabled on all servers. 

If you are using a non-Windows firewall, ignore this warning.