We've been running ZCS for serveral years now and have configured zimbra for external authentication pointing to three ldap servers (all replicas).
However recently we had an issue where one of the replicas needed to be bounced and we lost complete access to zimbra for authentication (users would connect and connections would time out trying to authenticate). Upon getting the ldap server in question brought back online, we noticed that this server was the one listed first on the list of servers to do authentication.
Clearly, there is no failover happening. What's the purpose then for having multiple ldap servers or is failover not working? Is there a timeout value somewhere that would make it the server use the next in line?