What is the purpose of software rollback in switch operations?

• A. Enables live software updates without reboot.
• B. Allows a switch to return to a previous, more reliable version of image or configuration files.
• C. Encrypts the software images for security.
• D. Restores factory default settings only.

Answer: (B)

Software rollback is a safety mechanism that lets a switch quickly return to a previously working state after a faulty upgrade or misconfiguration. It keeps a copy of the last known-good software image (and often the last good configuration). If the new software proves unstable or incompatible, the device can boot into that prior image or restore the prior configuration, restoring stability with minimal downtime. This is exactly what the option describing returning to a previous, more reliable version of the image or configuration files conveys.

The other ideas aren’t the same: live updates without reboot refer to seamless upgrades, not reversing to a prior state; encrypting images is about security, not restoring a previous working version; restoring factory defaults wipes to the original out-of-the-box state, not to a previously tested, reliable version.