Symptom

You are using Microsoft Internet Information Services IIS to provide firmware updates via HTTP for your IGEL devices (Windows or Linux based). When starting an update process, you receive an error message such as "File not available" or "File is not an archive", and the update process terminates unsuccessfully.

Problem

IIS does not offer files with unknown MIME types for the download and blocks the request coming from the device.

Solution

Make sure all files provided in the firmware update are added to the list of MIME types in IIS. Proceed as described in this Microsoft support document.

Add a new MIME type for files of extension (wildcard) '*' with a type of 'application/octet-stream'. This will provide a default MIME type for all files that have not already had one and bypass the blocking.

For security reasons, Microsoft does not recommend setting a wildcard that enables IIS to send out any kind of files. You may add every single file extension of your firmware update files to the list of MIME types instead.