I make use of the Ping Multi Datasource. I adjusted mine to automatically add in all IP Addresses listed in system.ips for the device. That way I know, if I lose PING to one of those IP's but HOST STATUS for the device is fine, then I know there's an issue with just that IP or network segment. I don't know if that will actually work if there's an issue with the WebLogic Application. Meaning, the weblogic app might stop serving up the website but the IP address might still be pingable.
Hope that helps!