CLI Configuration Mode Overview

Understanding Junos OS CLI Configuration Mode

• Configuration Mode Commands

• Configuration Statements and Identifiers

• Configuration Statement Hierarchy

Configuration Mode Commands

The following table summarizes each CLI configuration mode command. The commands are organized alphabetically.

Configuration Statements and Identifiers

You can configure device properties by including the corresponding statements in the configuration. Typically, a statement consists of a system-defined keyword, which is fixed text, and an optional 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.

Configuration Statement Hierarchy

The Junos OS configuration consists of a hierarchy of statements. There are two types of statements:

• Container statements, which are branches that can contain other statements (including additional container statements or leaf statements). Container statements at the top of the hierarchy are considered to be the trunk of the hierarchy tree.

• Leaf statements (contained by container statements) which do not contain other statements

The container and leaf statements form the configuration hierarchy. Each statement at the top level of the configuration hierarchy resides at the trunk of a hierarchy tree. These 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.

The following illustration shows the hierarchy tree, illustrating a statement path for the part of the protocol configuration hierarchy responsible for configuring the hello-interval statement on an interface in an OSPF area.

Figure 1: Configuration Mode Hierarchy of Statements

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). The hello-interval statement is a leaf on the tree, which in this case contains a data value, namely the length of the hello-interval, in seconds.

The following configuration example illustrates the statement hierarchy as shown in Figure 1:

The command displays the configuration as follows:

The CLI indents each level in the hierarchy to indicate each statement’s relative position in the hierarchy. Additionally, in general, it 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 lowest 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, 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#?
  Note

  When making configuration changes, if you exit configuration mode without committing them, the intended changes will be lost.

  You must have configure permission to view and use the configure command. When in configuration mode, you can view and modify only those statements for which you have access privileges.

• If you enter configuration mode and another user is also in configuration mode, a message shows the user’s name and the part of the configuration the other 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—such as 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 and 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:

Using Command Completion in Configuration Mode

To list the configuration mode commands, use the ? command by itself:

To list all the statements available at a particular hierarchy level, use ? after the name of the hierarchy level you wish to view. In this example, we are viewing the edit and edit protocols hierarchies.

To list all commands that start with a particular string or letter, enter the string and/or letter and end with the ? character. Here is a list of all the routing-options commands starting with the letter “a.”

This is a list of all configured Asynchronous Transfer Mode (ATM) interfaces, using just a partial completion (at?):

You can also show a list of all configured policy statements:

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]:

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 command hierarchy level and below.

Statements are listed alphabetically within each hierarchy and subhierarchy. If a subhierarchy is sufficiently long that it might be difficult to determine where it ends and its next peer statement begins, the subhierarchy appears at the end of its parent hierarchy instead of in alphabetical order. In this case, a placeholder appears in its actual alphabetical position.

For example, at the [edit interfaces interface-name unit logical-unit-number] hierarchy level, the family family-name subhierarchy has more than 20 child statements, including several subhierarchies with child statements of their own. The full family family-name hierarchy appears at the end of its parent hierarchy ([edit interfaces interface-name unit logical-unit-number]), and the following placeholder appears at its actual alphabetical position:

Another exception to alphabetical order is that the disable statement always appears first in any hierarchy that includes it.