From time to time you will find that your endpoints are unable to connect, through PXE, to the appropriate site server running Deployment Services. After researching the problem you discover that a Dummy.0 file exists in the preboot image directory. You delete the folder which contains this file, update your configuration, and watch the preboot environment regenerate. Now your remote endpoints are able to connect through PXE and you're able to successfully manage the machine.
The attached PowerShell script can be utilized in a custom inventory task, against site servers with deployment site services, on a regular basis. It will check for any existence of a dummy.0 file, and if found, report it up to your server. You should create an automation policy that executes a SQL query against the table. If results are found, it should e-mail you so you're alerted to this. Implentation instructions can be found in the attached PDF.