CLI Configuration Mode Overview

Understanding Junos OS CLI Configuration Mode

• Configuration Mode Commands

• Configuration Statements and Identifiers

• Configuration Statement Hierarchy

Configuration Mode Commands

Table 1 summarizes each CLI configuration mode command. The commands are organized alphabetically.

Configuration Statements and Identifiers

You can configure router or switch properties by including the corresponding statements in the configuration. Typically, a statement consists of a keyword, which is fixed text, and, optionally, an identifier. An identifier is an identifying name that you can define, such as the name of an interface or a username, which enables you and the CLI to differentiate among a collection of statements.

Table 2 describes top-level CLI configuration mode statements.

For specific information on configuration statements, see the Junos OS configuration guides.

Configuration Statement Hierarchy

The Junos OS configuration consists of a hierarchy of statements. There are two types of statements: container statements, which are statements that contain other statements, and leaf statements, which do not contain other statements (see Figure 1). All of the container and leaf statements together form the configuration hierarchy.

Figure 1: Configuration Mode Hierarchy of Statements

Each statement at the top level of the configuration hierarchy resides at the trunk (or root level) of a hierarchy tree. The top-level statements are container statements, containing other statements that form the tree branches. The leaf statements are the leaves of the hierarchy tree. An individual hierarchy of statements, which starts at the trunk of the hierarchy tree, is called a statement path. Figure 1 illustrates the hierarchy tree, showing a statement path for the portion of the protocol configuration hierarchy that configures the hello interval on an interface in an OSPF area.

The protocols statement is a top-level statement at the trunk of the configuration tree. The ospf, area, and interface statements are all subordinate container statements of a higher statement (they are branches of the hierarchy tree); and the hello-interval statement is a leaf on the tree which in this case contains a data value: the length of the hello interval, in seconds.

The CLI represents the statement path shown in Figure 1

as [edit protocols ospf area area-number interface interface-name] and displays the configuration as follows:

The CLI indents each level in the hierarchy to indicate each statement’s relative position in the hierarchy and generally sets off each level with braces, using an open brace at the beginning of each hierarchy level and a closing brace at the end. If the statement at a hierarchy level is empty, the braces are not printed.

Each leaf statement ends with a semicolon. If the hierarchy does not extend as far as a leaf statement, the last statement in the hierarchy ends with a semicolon.

The configuration hierarchy can also contain “oneliners” at the last level in the hierarchy. Oneliners remove one level of braces in the syntax and display the container statement, its identifiers, the child or leaf statement and its attributes all on one line. For example, in the following sample configuration hierarchy, the line level 1 metric 10 is a oneliner because the level container statement with identifier 1, its child statement metric, and its corresponding attribute 10 all appear on a single line in the hierarchy:

Likewise, in the following example, dynamic-profile dynamic-profile-name aggregate-clients; is a oneliner because the dynamic-profile statement, its identifier dynamic-profile-name, and leaf statement aggregate-clients all appear on one line when you run the show command in the configuration mode:

Entering and Exiting the Junos OS CLI Configuration Mode

• To enter configuration mode, use the configure command.

  When you enter configuration mode, the following configuration mode commands are available:

  user@host>configure

  [edit]

  user@host#?

  Users must have configure permission to view and use the configure command. When in configuration mode, a user can view and modify only those statements for which they have access privileges set. For more information, see the Junos OS Administration Library.

• If you enter configuration mode and another user is also in configuration mode, a message shows the user’s name and what part of the configuration the user is viewing or editing:

  Up to 32 users can be in configuration mode simultaneously, and they all can make changes to the configuration at the same time.

• To exit configuration mode, use the exit configuration-mode configuration mode command from any level, or use the exit command from the top level. For example:

  If you try to exit from configuration mode using the exit command and the configuration contains changes that have not been committed, you see a message and prompt:

• To exit with uncommitted changes without having to respond to a prompt, use the exit configuration-mode command. This command is useful when you are using scripts to perform remote configuration.

Issuing Relative Junos OS Configuration Mode Commands

The top or up command followed by another configuration command, including edit, insert, delete, deactivate, annotate, or show enables you to quickly move to the top of the hierarchy or to a level above the area you are configuring.

To issue configuration mode commands from the top of the hierarchy, use the top command; then specify a configuration command. For example:

To issue configuration mode commands from a location higher up in the hierarchy, use the up configuration mode command; specify the number of levels you want to move up the hierarchy and then specify a configuration command. For example:

Examples: Using Command Completion in Configuration Mode

List the configuration mode commands:

List all the statements available at a particular hierarchy level:

List all commands that start with a particular letter or string:

List all configured Asynchronous Transfer Mode (ATM) interfaces:

Display a list of all configured policy statements:

For information on what an angle bracket ( > ) and a plus sign (+) before the statement name indicate, see Adding Junos OS Configuration Statements and Identifiers.

Notational Conventions Used in Junos OS Configuration Hierarchies

When you are working in Junos OS command-line interface (CLI) configuration mode, the banner on the line preceding the prompt indicates the current hierarchy level. In the following example, the level is [edit protocols ospf]:

(The Junos OS documentation uses user@host# as the standard configuration mode prompt. In an actual CLI session, the prompt shows your user ID and the name of the Juniper Networks device you are working on.)

Use the set ? command to display the statements that you can include in the configuration at the current level. The help apropos command is also context-sensitive, displaying matching statements only at the current level and below.