During the online rebuild process, the Replication Server is in normal mode. All RepAgents and other Replication Servers are automatically disconnected from the Replication Server.
Replication Server is Rebuilding
Replication Servers and RepAgents retry connections periodically until rebuild queues has completed. At this time, the connections are successful.
If there are loss detection messages, you need to check the status of these messages. Depending on the failure condition, if these messages are no longer available at their source, you may need to rebuild the queues using off-line logs. Or, you can request that Replication Server ignore the lost messages.