- `iso_urls` ([]string) - Multiple URLs for the ISO to download. Packer will try these in order. If anything goes wrong attempting to download or while downloading a single URL, it will move on to the next. All URLs must point to the same file (same checksum). By default this is empty and `iso_url` is used. Only one of `iso_url` or `iso_urls` can be specified. - `iso_target_path` (string) - The path where the iso should be saved after download. By default will go in the packer cache, with a hash of the original filename and checksum as its name. - `iso_target_extension` (string) - The extension of the iso file after download. This defaults to `iso`.