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    User Interfaces to the Junos OS

    The Junos OS provides several user interfaces, including a command-line interface (CLI), the Junos XML management protocol, the NETCONF management protocol, and the J-Web graphical user interface. They are described in the following sections. For more information about the user interfaces, see the CLI User Guide.


    The Junos CLI is the user interface available when a user logs in to a router through the console or auxiliary port, or logs in remotely. The CLI has two modes: operational mode, which provides commands for monitoring the Junos OS, routing protocols, network interfaces and connectivity, and router hardware; and configuration mode, which provides commands for configuring the Junos OS.

    The Junos CLI provides the following functionality:

    • Context-sensitive name completion for commands, configuration statements, and other text strings, such as filenames and usernames. When you type only the initial part of a name and press the Tab key or the Spacebar, the CLI automatically adds the remainder of the name if there is only one possible completion. If multiple completions are possible, the CLI lists them and displays a short description of each.

      Similarly, if you type a question mark (?) after the starting portion of a term (word) in a command or configuration statement, or after a complete term and a following space, the CLI displays the terms that can be specified at that position in the command or statement, along with a short description of each.

    • Keyword search for commands and configuration statements (similar to the UNIX apropos command). The help apropos topic command displays all commands or configuration statements that include the specified topic word or phrase in their names or short description. In configuration mode, this feature is context-sensitive—the CLI displays only the matching terms that are valid at or below the current level in the configuration hierarchy.
    • Automatic display of one screen at a time when command output or the list of possible completions is longer than the screen length (similar to the effect of the UNIX more utility). You can scroll backward and forward through the screen output and search for text strings in it.
    • Keyboard sequences for editing the command line and moving the cursor on it, and for scrolling through a list of recently executed commands. The keyboard sequences are the same as those used in the UNIX editor Emacs. For example, when you type Ctrl+b, the cursor moves backward one character.
    • Tracking of commands issued during the current CLI session. To display them, issue the show cli history command.

    You can customize your CLI environment in the following ways:

    • Define the terminal type as ANSI, VT100, or regular or small xterm.
    • Disable command completion.
    • Display helpful hints about how to use the CLI.
    • Enable an automatic prompt for the user to restart the router after a software upgrade. Restarting is required for the new software to take effect.
    • Set the CLI prompt.
    • Set the duration that a login session can be idle before it is terminated.
    • Set the screen length, width, or both.

    You can apply filters to command output to change the CLI’s standard display behavior in the following ways:

    • Count the number of lines in the output instead of displaying the actual output.
    • Display only text that matches or does not match a pattern. The Junos OS supports the use of extended (modern) regular expressions as defined in POSIX 1003.2.
    • Display all output at once (override the default behavior of displaying one screen of output at a time).
    • Display only the final lines of output.
    • Suppress redisplay of the CLI prompt at the end of command output.
    • Save (redirect) the screen output to a file.

    When displaying the current configuration, you can filter the output in the following ways in addition to those in the preceding list:

    • Compare the current configuration with a previously saved configuration.
    • Display additional information about the configuration, including the version of the Junos OS under which the configuration was created.

    You can also apply multiple filters in sequence, and write scripts that customize the output in ways not provided by the CLI. For information about scripting, see the Automation Scripting Feature Guide.

    For detailed information about the CLI features described in this section, see the CLI User Guide.

    Junos XML API, Junos XML Management Protocol, and NETCONF Management Protocol

    The Junos Extensible Markup Language (XML) application programming interface (API) defines XML tag elements that correspond to all Junos configuration statements and many operational commands. XML is a language for defining a set of markers (tag elements) that are applied to a data set or document to describe the function of individual elements and codify the hierarchical relationships between them.

    The Junos XML management protocol enables client applications to exchange information with Juniper Networks devices. The Junos XML management protocol defines XML tag elements that retrieve and change Junos configuration objects, which are represented by the XML tag elements in the Junos XML API.

    The NETCONF management protocol is similar in function to the Junos XML management protocol and is defined in RFC 4741, NETCONF Configuration Protocol. The NETCONF server and client applications use the SSH protocol for communication in accordance with RFC 4742, Using the NETCONF Configuration Protocol over Secure SHell (SSH).

    J-Web User Interface

    The J-Web user interface is a graphical user interface that enables you to configure and monitor Juniper Networks devices through an Internet browser. The J-Web interface includes the following features:

    • Quick Configuration pages for performing basic configuration operations
    • Monitoring tools that display system status, routes, and statistics
    • Diagnostic tools
    • A View Events page that displays system log messages
    • File utilities for managing configuration files, licenses, and temporary files

    Modified: 2018-01-03