Question about cluster replication security considerations for ISPConfig
I've been running ISPConfig happily for a while now all under one server, one datacenter for my needs. I recently decided for the sake of availability I would also collocate at a second datacenter, which happens to be with a different provider. In looking through the mechanisms to replicate, I determined I needed to ask a couple security-related questions to determine what the best course of action would be.
#1 - It looks like ISPConfig's default mechanism for replication is basically database replication. Is this correct?
#2 - Assuming #1, is this done via any secure mechanism at all? Or is it done in the clear with the intention that all the machines would be behind the same firewall?