Enterprise Manager Configuration Assistant - Oracle 10g/11g Data and Database Management Utilities - page 360

The configuration changes won't be considered until Enterprise Manager restarts, so
you should stop and start the console at your earliest convenience.
emctl stop dbconsole db
emctl start dbconsole db
When accessing the console a warning will be displayed in the browser window,
letting the user know that there are problems with the certificate, even though the
certificate structure is valid, this is issued by a not known Certificate Authority. You
can accept the certificate and proceed with your session.
You can verify the change in the agent configuration, this was also modified and
the upload process will be performed in HTTPS mode too. Issue the emctl status
agent to verify the change.
Summary
Today, efficient database interactive administration cannot easily be achieved
without Enterprise Manager, this does not mean the command line interface is
obsolete, it simply means that using commands to perform the daily database
management tasks will take longer than using the graphical interface.
Considering this, keeping Enterprise Manager DB Control Console available will
provide the DBA with a more efficient way to easily manage the complexities of
Oracle databases. The tool to assist the DBA in making sure EM will be properly
configured is the EMCA, and as we have seen, the EMCA is much more than just a
tool to initially configure the console. It is a tool that allows the DBA to customize the
nuts and bolts of the console.
On the other hand, keeping the software up to date is a good practice, it wipes off
known bugs and it lets you prevent possible security breaches with a more robust
and secure software version. OPatch is the tool that allows you to manage your
software updates related to Critical Patch Updates ( CPU ) or individual patches. In
the next chapter OPatch will be explored.