Junos OS CLI Guide Overview
This guide explains how to use the Junos OS command-line interface (CLI) to monitor device status and configure Junos OS devices. It covers CLI modes (operational and configuration), candidate versus active configuration behavior, and common CLI usage features such as online help and command completion.
Documented Specifications and Technical Notes
| Artikel | Details (from source) |
|---|---|
| Dokumenttyp | Junos OS CLI User Guide for Junos OS |
| Published date | 2026-06-18 |
| Current-information note | “The information in this document is current as of the date on the title page.” |
| Underlying OS kernel | The CLI runs on top of the FreeBSD UNIX-based operating system kernel for Junos OS. |
| CLI modes | Operational mode (monitor/troubleshoot) and configuration mode (enter statements to configure device properties). |
| Configuration model | Edits are made to the candidate configuration; changes are not implemented until you commit. Candidate changes can be made without operational impact until commit. |
| Year 2000 / time-related compliance | Junos OS has no known time-related limitations through 2038; however, the NTP application is known to have some difficulty in 2036. |
| Exclusive configuration behavior | In configure exclusive mode, uncommitted changes are discarded when you exit (optionally prompting for discard/rollback). |
Quick Start: Accessing the CLI and Making Configuration Changes
- Ensure your device hardware is set up and Junos OS is installed.
- Use a direct console connection or network access using SSH or Telnet.
- Anmelden als
root(root has superuser privileges). - Start the CLI from your login session.
- Verwenden Betriebsmodus commands to display current device status (for monitoring and troubleshooting).
- Verwenden Konfigurationsmodus to change device settings by adding configuration statements to the candidate configuration (edits do not affect the active configuration until you commit).
- When finished, commit the candidate configuration so it becomes the operational (active) configuration.
Troubleshooting (Source-Grounded)
- Missing mandatory statement in configuration hierarchy: When you omit a required statement and then move to a different hierarchy level or run a
showcommand in configuration mode, the CLI displays a message indicating which statement is missing (example shown: missing mandatory statement:'mode'). - Configuration exit without committing (exclusive mode): In
configure exclusivemode, exiting can trigger a prompt about discarding uncommitted changes and an auto-rollback to the previously committed state. Use theyesoption to discard/rollback, ornoto continue editing/commit later. - Commit/access errors after an automatic rollback: Wenn Sie
commit confirmedand do not confirm within the specified interval, an automatic rollback occurs. After that, the messageerror: access has been revokedmay appear for subsequent commit attempts. To re-lock the configuration for exclusive editing, you must start a newconfigure exclusiveSitzung.
Häufig gestellte Fragen
- What are the two CLI modes in Junos OS?
- The CLI has two modes: operational mode (to display current status and to monitor/troubleshoot) and configuration mode (to enter statements that configure device properties).
- When do configuration changes take effect on the device?
- Edits are made to the candidate configuration. The device does not implement candidate changes in the active (operational) configuration until you commit.
- How can I discover what commands are available at a hierarchy level?
- If you type a question mark (?) at a command hierarchy level, the CLI displays a list of available commands with short descriptions for that level.
- What happens if I omit a required statement in configuration mode?
- When you attempt to move from that hierarchy level or issue a show command in configuration mode, the CLI indicates which mandatory statement is missing (for example, a missing 'mode' statement).
- Why might I see “access has been revoked” when committing?
- If you initiate configure exclusive, run commit confirmed, and do not confirm within the specified interval, an automatic rollback occurs and the exclusive lock is removed; subsequent commit attempts can then show error: access has been revoked.
Dokumente / Ressourcen
 | OS CLI User |
Verweise
- apps.juniper.net/cli-explorer/apps.juniper.net
- apps.juniper.net/feature-explorer/apps.juniper.net
- pathfinder.juniper.net/compliance/pathfinder.juniper.net
- support.juniper.net/support/eula/support.juniper.net
- supportportal.juniper.net/s/article/EXQFX-Transfer-on-commit-using-SFTP-fails-if-SSH-host-keys-are-not-configured?language=en_USsupportportal.juniper.net
- juniper.net/documentation/content-applications/cli-explorer/junos/www.juniper.net
- juniper.net/documentation/en_US/junos/information-products/pathway-pages/config-guide-automation/config-guide-automation.htmlwww.juniper.net
- juniper.net/documentation/en_US/junos/information-products/pathway-pages/config-guide-high-availability/high-availability.htmlwww.juniper.net
- juniper.net/documentation/en_US/junos/information-products/pathway-pages/netconf-guide/netconf.htmlwww.juniper.net
- juniper.net/documentation/en_US/junos/information-products/pathway-pages/network-management/network-management.htmlwww.juniper.net
- Bedienungsanleitungmanual.tools
Published: August 24, 2026