Answers:
1) No, you need to order the Recovery CD.
2) There are 2 types of files: System and Recovery.
The System Images (-sys-) are used only for installing on sensors that support ROMMON (like the IDS-4215, IPS-4240, and IPS-4255). The sensors supporting ROMMON do not have CDROM drives, and so the image must be tftpd to the sensor through ROMMON.
The System Images are used for disaster recovery where the harddrive/compactflash of the sensor has been seriously corrupted or a new blank harddrive/compactflash has been placed in the sensor.
The Recovery Inages (-r-) only updated the Recovery Partition of the sensor. They must be installed from a running Application Partition. The .pkg is a special extension specific to the Cisco IDS application. There are special methods for unpackaging and installing the unerlying files.
Under ordinary situations the user will constantly be updating their sensor software through the normal upgrade process using Major Updates (-maj-), Minor Updates (-min-), Service Packs (-sp-), or Signature Updates (-sig-).
It is only in the case that the Application Partition becomes corrupted that a user ever needs to boot to the Recovery Partition and load a new Application Partition.
Most users will never update their Recovery Partition. So users who purchased the IDS-4235 for example with 4.0(1) software will have a 4.0(1) Recovery Image. If they later upgrade to 4.1(1) and experience a corruption then they can always boot the Recovery Partition and reload 4.0(1). If they don't want to have to go back to 4.0(1) we supply a Recovery Image to update the Recovery Partition to 4.1(1).
The only time a Recovery CD is really necessary is when the user is going from 3.x to 4.x, because of the drastic change between the 2 versions, or if the Recovery Partition has also been corrupted, or if a blank harddrive is being used.
3.
I don't think either the Recovery nor System Images contain the necessary files for creating a Recovery CD. If I remember right additional files were added to the Recovery CD to make it bootable that were not needed on the System Images or Recovery Images since they relied on a sensor that was already running.
