What command is used to replace the current configuration with a new one?

The command used to replace the current configuration with a new one is "load override." This command allows an administrator to load a configuration file while completely replacing the existing configuration on the device. It ensures that the current configuration is removed and the new configuration is applied as the active configuration.

"Replace config," "set config," and "commit load" are not valid commands for this function. "Replace config" does not exist as a command in Junos OS for loading configurations. "Set config" is used to modify specific parts of the configuration but does not load a new configuration entirely. "Commit load" is a command that is typically associated with loading a saved configuration after it has been modified and does not replace the existing configuration in the way that "load override" does.

Thus, understanding the use of the "load override" command is crucial for network administrators when they need to ensure a completely new configuration is deployed without retaining any prior settings.