We should know where the Selenium Server is running.
This is Java Code :
we have straight method for this in HttpCommandExecutor
class, getAddressOfRemoteServer()
code for Firefox :
RemoteWebDriver rcw = new RemoteWebDriver(new URL("http://serveraddress:portnumber/wd/hub"), DesiredCapabilities.firefox())
so if you have an instance of RemoteWebDriver
rcw.getCommandExecutor().getAddressOfRemoteServer()
code for IE :
Same as Above OR for Local
((HttpCommandExecutor)(new InternetExplorerDriver().getCommandExecutor())).getAddressOfRemoteServer();