It’s very easy to build a Data Guard using Enterprise Manager Cloud Control (I’ll surely blog about it soon) and it’s also possible to manage your existing Data Guards with Enterprise Manager Cloud Control. Enterprise Manager will automatically detect Data Guard configuration of the target databases but if you need to administer your Data Guard with Enterprise Manager, your database should be configured by Data Guard broker. One of the good thing is, Enterprise Manager Cloud Control also help you to set up Data Guard broker for existing Data Guards with a few clicks.
First of all, you should deploy Enterprise Manager agents to the both primary and standby servers. Then you should add these databases (including standby database) to Enterprise Manager. While adding standby database, Enterprise Manager will complain that it will not be able to monitor it because standby database is read-only (11g Active Data Guard) or in mounted mode. Ignore the warning and add the standby database without monitoring. If you do not have a DNS in your network to resolve host names, make sure that you add hostnames and IP address to /etc/hosts file of primary and standby servers. So you should be able to resolve the hostname of standby server on primary server, and resolve the hostname of standby server on primary server.
If it is not an Active Data Guard, Enterprise Manager agent will not be able to connect your standby database and you’ll see your standby database is “down”. That’s not a problem, ignore the status of standby database for now.