Cisco Cisco IPS 4255 Sensor

A signature engine update is an executable file containing binary code to support new signature updates. 
Signature engine files require a specific service pack, which is also identified by the req designator.

 illustrates what each part of the IPS software file represents for signature engine updates.

Recovery and system image files contain separate versions for the installer and the underlying 
application. The installer version contains a major and minor version field. The major version is 
incremented by one of any major changes to the image installer, for example, switching from .tar to rpm 
or changing kernels. The minor version can be incremented by any one of the following:

Minor change to the installer, for example, a user prompt added.

Repackages require the installer minor version to be incremented by one if the image file must be 
repackaged to address a defect or problem with the installer.

 illustrates what each part of the IPS software file represents for recovery and system image files.

191861

Product line designator

Package type

Signature engine level

Software version requirement designator

Required software version

File extension

191015

Product line/platform designator

Strong crypto designator

Package type

Installer major version

Installer minor version

Application version designator

Application version

File extension