I want install Zimbra Network 5.0.10 in single mode with 2 servers (active and standby) with Red Hat 5.2 installed.

Active node: bs6.mailzimbra.es
Standby node: bs7.mailzimbra.es
Cluster service hostname: cluster.mailzimbra.es

I'm following the manual for installation in single mode, but the step where i have to change the hostname and LDAP master hostname to hostname cluster service i don't understand it, in fact the installation process fails at this point because the LDAP service can't initialize with this change.

Must I have a server for the cluster service or the cluster service share the same server with the active node?.

Has the cluster service the same ip address that the active node?