In preparation of your CCNA Security 640-553 exam, we want to make sure we cover the topics that you will encounter on your CCNA exam. So to assist you, below we will discuss the CCNA Security concept, Securing the Cisco IOS image and configuration file. As you progress through your CCNA exam studies, I am sure with repetition you will find that all the topics become much easier. So even though this may be a difficult concept initially, keep at it as no one said getting your Cisco certification would be easy!

The Cisco IOS resilient configuration feature enables a router to secure and maintain a working copy of the running image and configuration so that those files can withstand malicious attempts to erase the contents of persistent storage (NVRAM and flash storage).

A great challenge for network operators is the total downtime that is experienced after a router has been compromised and its operating software and configuration data are erased from its persistent storage. The operator must retrieve an archived copy (hopefully one is available) of the configuration and a working Cisco IOS image to restore the router. Recovery must then be performed for each affected router, adding to the total network downtime.

The Cisco IOS resilient configuration feature is intended to speed up the recovery process. This feature maintains a secure working copy of the router image and the startup configuration at all times. The user cannot remove these secure files. This set of Cisco IOS image and router running configuration files is referred to as the bootset.

For example, the show flash command will not show the secure image file. If a router has been compromised, the resulting down time is reduced because the router maintains secure archives of the required files and there is no need to search for backups of these files elsewhere.

The command sequence to save a primary bootset to a secure archive in persistent storage is as follows:

We hope you found this Cisco CCNA Security 640-553 certification article helpful. We pride ourselves on not only tons of free Cisco CCNA exam information, but also providing you with the real world Cisco CCNA skills to advance in your networking career as you exercise the many CCNA lab scenarios in our lab workbooks.