11-8z Saving the Current Configurationz Setting Configuration Rollbackz Specifying a Startup Configuration File for the Next System Startupz Backing Up the Startup Configuration Filez Deleting the Startup Configuration File for the Next Startupz Restoring the Startup Configuration Filez Displaying and Maintaining Device ConfigurationConfiguration File OverviewA configuration file saves the device configurations in command lines in text format. You can viewconfiguration information conveniently through configuration files.Types of configurationThe configuration of a device falls into two types:z Startup configuration, a configuration file used for initialization when the device boots. If this filedoes not exist, the system boots using null configuration, that is, using the default parameters.z Current configuration, which refers to the currently running configuration of the system. Thecurrent configuration may include the startup configuration if the startup configuration is notmodified during system operation, and it also includes the new configuration added during thesystem operation. The current configuration is stored in the temporary storage medium of thedevice, and will be removed when the device reboots if not saved.Format of a configuration fileA configuration file is saved as a text file. It:z Saves configuration in the form of commands.z Saves only non-default configuration settings.z Lists commands in sections by views, usually in the order of system view, interface view, androuting protocol view. Sections are separated with one or multiple blank lines or comment linesthat start with a pound sign #.z Ends with a return.Coexistence of multiple configuration filesMultiple configuration files can be stored on a storage medium of a device. You can save theconfiguration used in different environments as different configuration files. In this case, when thedevice moves between these networking environments, you just need to specify the correspondingconfiguration file as the startup configuration file for the next boot of the device and restart the device,so that the device can adapt to the network rapidly, saving the configuration workload.A device boots using only one configuration file. However, you can specify two startup configurationfiles, main and backup startup configuration file, for the next startup of the device as needed and whenthe device supports this feature. When the device boots, the system uses the main startupconfiguration file, and if the main startup configuration file is corrupted or lost, the system will use thebackup startup configuration file for device boot and configuration. The devices supporting theconfiguration of the main and backup startup configuration files, compared with the devices that do notsupport this feature, are more secure and reliable.
