Description: The source of the script. This is an ASCII string similar to a URL, and must be in one of the following formats: - 'bootp://' - the source of the script will be determined using bootp. - 'usb://' - the script will be loaded from the usb port of the switch, if not in stack, or from the usb port of the base unit, if in stack. - 'usb:///' - the script will be loaded from the usb port of the switch, if not in stack, or from the usb port of the specified unit, if in stack. The unit number must be between 1 and 8. - 'tftp:///' - the script will be loaded using TFTP from the specified IP address. - 'tftp:///' - the script will be loaded using TFTP from the specified host. The hostname must have at most 64 characters in length. - 'sftp:///' - the script will be loaded using SFTP from the specified IP address. - 'sftp:///' - the script will be loaded using SFTP from the specified host. The hostname must have at most 64 characters in length. In each of the supported formats, the filename must have at most 255 characters in length. If this column is empty, it indicates that the entry is not in use.