Editing and Committing a Configuration

When you edit a configuration, you work in a copy of the current configuration to create a candidate configuration. The changes you make to the candidate configuration are visible through the user interface immediately, but do not take effect on the Services Router until you commit the changes. When you commit the configuration, the candidate file is checked for proper syntax, activated, and marked as the current, operational software configuration file. If multiple users are editing the configuration when you commit the candidate configuration, all changes made by all the users take effect.

If you are editing the configuration with the CLI, you can edit an exclusive or private candidate configuration. For more information, see Entering and Exiting Configuration Mode.

When you commit a configuration, the Services Router saves the current operational version and the previous 49 versions of committed configurations. The most recently committed configuration is version 0 (the current operational version), and the oldest saved configuration is version 49. You can roll back the configuration to any saved version. Version 0 is stored in the file juniper.conf, and the last three committed configurations are stored in the files juniper.conf.1.gz, juniper.conf.2.gz, and juniper.conf.3.gz. These four files are located in the /config directory, and the remaining 46 previous versions of committed configurations—files juniper.conf.4.gz through juniper.conf.49.gz—are stored in the /var/db/config directory.

Note: You must assign a root password before committing a configuration. For more information, see the JUNOS Software Installation and Upgrade Guide.