The configure exclusive command is used to enter configuration mode while simultaneously placing an exclusive lock on the candidate configuration database. This lock prevents any other user from making changes or committing a configuration until the user who issued the command either commits their changes or exits configuration mode. This directly addresses the scenario's requirement to prevent other users from modifying or discarding your in-progress edits.

A. configure master: This is not a valid Junos OS command. The term 'master' refers to the primary configuration database, but this command does not exist to access it in this manner.

B. cli privileged: This is not a valid Junos OS command. User access levels and permissions in Junos are determined by the user's configured login class, not by a specific command.

D. configure: This command enters a shared configuration mode. In this mode, multiple users can edit the candidate configuration simultaneously, which does not prevent others from modifying or overwriting your changes.

Juniper Networks TechLibrary

CLI User Guide

"Enter Configuration Mode" section: This official guide details the different commands for entering configuration mode. It explicitly states

"To enter configuration mode and lock the candidate configuration for as long as you remain in configuration mode

use the configure exclusive command... you prevent other users from committing changes."

URL: https://www.juniper.net/documentation/enUS/junos/topics/task/configuration/junos-os-cli-configuration-mode-entering.html

Juniper Networks TechLibrary

CLI User Guide

"Locking and Unlocking the Configuration" section: This section further clarifies the behavior of configuration locks. "When one user edits the configuration

another user can also edit the configuration. If the first user commits the configuration

the changes made by the second user are not lost... To prevent this

you can lock the configuration."

URL: https://www.juniper.net/documentation/enUS/junos/topics/task/configuration/junos-os-configuration-locking-and-unlocking.html