Upgrading Junos Software

C

The correct command to issue for upgrading the current software on Junos devices is option A, "request system software replace."

Here's a detailed explanation of why this is the correct option:

Junos software upgrades involve replacing the current version of the software with a new version. The "request system software replace" command initiates the process of replacing the current software with a new version.

When you issue this command, the Junos device will perform the following steps:

1. Verify that the new software package is valid and can be installed on the device.
2. Copy the new software package to the device's storage.
3. Install the new software package on the device.
4. Reboot the device to activate the new software.

It's important to note that when you issue the "request system software replace" command, the device will immediately begin the upgrade process and will reboot automatically when the upgrade is complete. Therefore, it's essential to ensure that you have saved any unsaved configurations before initiating the upgrade process.

The other options listed in the question are not correct for upgrading the software on a Junos device:

• Option B, "request system software install," is used to install new software packages but not to upgrade existing software.
• Option C, "request system software add," is used to add new software packages to the device but not to upgrade existing software.
• Option D, "request system software upgrade," is not a valid Junos command.