Chapter 5. CLI and System Management

Using the CLI

CLI Operational Mode

CLI Configuration Mode

System Management with SNMP

Configuring SNMP

The command-line interface (CLI) is the interface to the software that you use when you log in to the router. The CLI, which automatically starts after the router finishes booting, provides commands that you use to configure, monitor, and troubleshoot the router.

You can also use the JUNOScript API to access the router. This API is an XML application that Juniper Networks routers use to exchange information with client applications. It defines tags for describing the components and configuration of routers. For more information, see the JUNOScript technical documentation.

The CLI has two modes: operational and configuration. In operational mode, you monitor and troubleshoot the software, network connectivity, and the router by entering commands. In configuration mode, you configure the JUNOS software by creating a hierarchy of configuration statements. When you have finished entering the configuration statements, you commit them, which activates the configuration on the router.

The CLI commands and statements are organized hierarchically, with commands or statements that perform a similar function grouped together under the same level. For example, all commands that display information about the system and the system software are grouped under the show command, and all commands that display information about the routing table are grouped under the show route command. Figure 5.1 illustrates a portion of the show command hierarchy.

Figure 5.1. CLI Command Hierarchy Example