The JConsole setup has two parts: a server end and a client end. For this example, the Enterprise Server domain is installed on a machine called appserver.sun.com, which is a powerful Solaris server. This is the server end.
The client end also has an installation of Enterprise Server. Let us assume that the client end is a Windows machine with Java SE 6.0 and Enterprise Server installed.
The Enterprise Server installation is needed on the client end only when your Enterprise Server domain has security enabled on the remote machine (the default for cluster and enterprise profiles). If you just want to administer an Enterprise Server developer profile domain on the Solaris machine above, you do not need the Enterprise Server installation on this client machine.
If the server and client ends are on the same machine, you can use localhost to specify the host name.