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CLI Operational Mode Overview

In the operational mode, you can use Junos OS CLI commands to monitor and troubleshoot the device. The monitor, ping, show, test, and traceroute commands let you display information and test network connectivity for the device.

Overview of Junos OS CLI Operational Mode Commands

This topic provides an overview of Junos OS CLI operational mode commands.

CLI Command Categories

There are several broad categories of CLI commands, including:

  • Operational mode commands for monitoring and troubleshooting—The following commands perform functions related to information and statistics about the software and to test network connectivity.

    • clear—Clear statistics and protocol database information.

    • file—Perform file operations.

    • mtrace—Trace a multicast path from source to receiver.

    • monitor—Perform real-time debugging of various software components, including the routing protocols and interfaces.

    • ping—Determine the reachability of a remote network host.

    • show—Display the current configuration and information about interfaces, routing protocols, routing tables, routing policy filters, system alarms, and the chassis.

    • test—Test the configuration and application of policy filters and autonomous system (AS) path regular expressions.

    • traceroute—Trace the route to a remote network host.

  • Commands for restarting software processes—The commands in the restart hierarchy restart the various Junos OS processes, including the routing protocol, interface, and SNMP.

  • A command—request—for performing system-level operations, including stopping and rebooting the router or switch and loading Junos OS images.

  • A command—start—to exit the CLI and start a UNIX shell. For information about this command, see the CLI Explorer.

  • A command—configure—for entering configuration mode, which provides a series of commands that configure Junos OS, including the routing protocols, interfaces, network management, and user access.

  • For more information about the CLI operational mode commands, see the CLI Explorer. Alternatively, you can also enter ? at the operational mode command prompt to view a list of available commands.

Commonly Used Operational Mode Commands

The following table lists some operational commands you may find useful for monitoring router or switch operation. For a complete description of operational commands, see the Junos OS and Junos OS Evolved command references.

Table 1: Commonly Used Operational Mode Commands

Items to Check



Software version

Versions of software running on the router or switch

show version

Log files

Contents of the log files


Log files and their contents and recent user logins

show log

Remote systems

Host reachability and network connectivity


Route to a network system



Current system configuration

show configuration

Manipulate files

List of files and directories on the router or switch

file list

Contents of a file

file show

Interface information

Detailed information about interfaces

show interfaces


Chassis alarm status

show chassis alarms

Information currently on craft display

show chassis craft-interface

Router or switch environment information

show chassis environment

Hardware inventory

show chassis hardware

Routing table information

Information about entries in the routing tables

show route

Forwarding table information

Information about data in the kernel’s forwarding table

show route forwarding-table

Understanding the Display Options of the show Command

The show command can include brief, detail, extensive, or terse options. You can use these—as well as other options—to control the amount and type of information you want to view.

  1. At any point in the CLI, you can enter the ? character to view all the currently available options. For example:

  2. Choose the option you wish to use with the command.

Figure 1: Command Output OptionsCommand Output Options

Interface Naming Conventions Used in Operational Commands

This topic explains the interface naming conventions used in operational commands.

Physical Part of an Interface Name

The physical interface naming conventions for Juniper Networks device platforms is as follows:

  • On SRX devices, the unique name of each network interface has the following format to identify the physical device that corresponds to a single physical network connector:

  • On other platforms, when you display information about an interface, you specify the interface type, the slot in which the Flexible PIC Concentrator (FPC) is installed, the slot on the FPC in which the PIC is located, and the configured port number.

    In the physical part of the interface name, a hyphen (-) separates the media type from the FPC number, and a slash (/) separates the FPC, PIC, and port numbers:


Exceptions to the type-fpc/pic/port physical description include the aggregated Ethernet and aggregated SONET/SDH interfaces, which use the syntax aenumber and asnumber, respectively.

Logical Part of an Interface Name

The logical unit part of the interface name corresponds to the logical unit number, which can be a number from 0 through 16,384. Logical unit numbers are used to uniquely identify physical or virtual storage systems within a network. In the virtual part of the name, a period (.) separates the port and logical unit numbers:

  • SRX devices:

  • Other platforms:

Channel Identifier Part of an Interface Name

The channel identifier part of the interface name is required only on channelized interfaces. For channelized interfaces, channel 0 identifies the first channelized interface. For channelized intelligent queuing (IQ) interfaces, channel 1 identifies the first channelized interface.


Depending on the type of channelized interface, up to three levels of channelization can be specified.

A colon (:) separates the physical and virtual parts of the interface name:

  • SRX devices:

  • Other platforms:

Using Wildcard Characters in Interface Names

You can use wildcard characters in operational commands to specify groups of interface names without having to type each name individually. The following table lists the available wildcard characters. You must enclose all wildcard characters except the asterisk (*) in quotation marks (“ ”).

Table 2: Wildcard Characters for Specifying Interface Names

Wildcard Character


* (asterisk)

Match any string of characters in that position in the interface name. For example, so* matches all SONET/SDH interfaces.


Match one or more individual characters in that position in the interface name. For example, so-“[03]”* matches all SONET/SDH interfaces in slots 0 and 3.


Match all characters except the ones included in the brackets. For example, so-“[!03]”* matches all SONET/SDH interfaces except those in slots 0 and 3.


Match a range of characters. For example, so-“[0-3]” * matches all SONET/SDH interfaces in slots 0, 1, 2, and 3.


Match all characters that are not in the specified range of characters. For example, so-”[!0-3]”* matches all SONET/SDH interfaces in slots 4, 5, 6, and 7.