juniper commands cheat sheet

juniper commands cheat sheet

In the realm of network management and configuration, Juniper Networks devices are renowned for their robust features and reliability. Whether you're a network administrator, engineer, or technician, mastering Juniper commands is essential for efficient device management, troubleshooting, and configuration. This comprehensive Juniper commands cheat sheet aims to equip you with the most commonly used commands, best practices, and tips to streamline your workflow. From basic device management to advanced troubleshooting, this guide covers everything you need to optimize your Juniper network devices.

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Understanding the Juniper CLI Environment

Before diving into specific commands, it's important to understand the Juniper Command Line Interface (CLI) environment.

CLI Modes

Juniper devices operate in different CLI modes, each serving specific purposes:

• Operational Mode: Used for viewing device status, monitoring, and troubleshooting. It is the default mode after login.
• Configuration Mode: Used for configuring device settings. Enter this mode via the configure command.

Common CLI Commands Overview

| Command | Purpose | |--------------------------------|-------------------------------------------------------| | show | Display device status, configuration, or operational info | | commit | Apply configuration changes | | edit | Enter configuration hierarchy | | ping | Test network connectivity | | traceroute | Trace the path to a destination | | restart | Restart a specific process or the device | | request | Request system actions like reboot or firmware upgrade |

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Basic Juniper Commands for Device Management

Login and Access

• Connect via SSH:

```bash ssh username@device_ip ```

• Access the CLI:

```bash cli ```

Viewing Device Information

• Show system information:

```bash show version ```

• Show hardware details:

```bash show chassis hardware ```

• Display interface status:

```bash show interfaces terse ```

• Check routing tables:

```bash show route ```

Monitoring System and Network Status

• View system uptime:

```bash show system uptime ```

• Display system logs:

```bash show log messages ```

• Check active sessions:

```bash show system connections ```

Managing Interfaces

• View detailed interface info:

```bash show interfaces detail ```

• Check interface statistics:

```bash show interfaces extensive ```

• Enable or disable an interface:

```bash set interfaces ge-0/0/0 disable delete interfaces ge-0/0/0 disable ```

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Configuration Commands and Best Practices

Entering Configuration Mode

To modify settings, enter configuration mode: ```bash configure ``` Exit after changes: ```bash commit exit ```

Common Configuration Tasks

• Configure an IP address on an interface:

```bash edit interfaces ge-0/0/0 set unit 0 family inet address 192.168.1.1/24 commit ```

• Set hostname:

```bash set system host-name MyJuniperDevice commit ```

• Configure DNS servers:

```bash set system name-server 8.8.8.8 set system name-server 8.8.4.4 commit ```

• Configure default route:

```bash set routing-options static route 0.0.0.0/0 next-hop 192.168.1.254 commit ```

Managing Security Settings

• Create a firewall filter:

```bash edit firewall family inet filter BLOCK_SSH set term BLOCK_TERM from port ssh set term BLOCK_TERM then reject commit ```

• Apply filter to interface:

```bash set interfaces ge-0/0/0 unit 0 family inet filter input BLOCK_SSH commit ```

Saving and Loading Configurations

• Save configuration:

```bash save ```

• Load a saved configuration:

```bash rollback ```

• Commit configuration:

```bash commit ```

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Advanced Commands for Troubleshooting

Ping and Traceroute

• Basic ping test:

```bash ping 8.8.8.8 ```

• Extended ping:

```bash ping 8.8.8.8 rapid count 10 ```

• Traceroute:

```bash traceroute 8.8.8.8 ```

Monitoring and Diagnosing

• Show routing table:

```bash show route ```

• Display BGP peers:

```bash show bgp neighbor ```

• Check ARP table:

```bash show arp ```

• View active TCP connections:

```bash show system connections ```

Process Management

• Restart a process:

```bash restart routing daemon ```

• Reboot the device:

```bash request system reboot ```

• Shutdown the device:

```bash request system power-down ```

Packet Capture and Traffic Analysis

• Capture packets on an interface:

```bash monitor traffic interface ge-0/0/0 matching "tcp" ```

• Save captured packets:

```bash monitor traffic interface ge-0/0/0 export capture.pcap ```

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Automation and Scripting with Juniper Commands

Juniper devices support scripting and automation to streamline repetitive tasks.

Using Junos CLI Scripts

• Scripts can be written in Python, Expect, or Junoscript.
• Example of running a script:

```bash file copy /var/tmp/myscript.py /var/tmp/ run /var/tmp/myscript.py ```

Batch Commands with Commit and Rollback

• Make multiple configuration changes:

```bash edit set system host-name NewHostName set interfaces ge-0/0/1 unit 0 family inet address 192.168.2.1/24 commit confirmed 5 ```

• Rollback if issues occur:

```bash rollback 0 ```

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Tips and Best Practices for Using Juniper Commands

• Always back up your configuration before making significant changes:

```bash save /var/tmp/backup.conf ```

• Use commit confirmed for risky changes:

```bash commit confirmed ```

• Regularly update your device firmware and Junos OS for security and feature improvements.
• Keep a record of configuration changes for audit purposes.
• Use descriptive names for interfaces, filters, and policies to simplify management.

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Conclusion

Mastering the Juniper commands cheat sheet is vital for effective network management, troubleshooting, and configuration. This guide provides a solid foundation of the most essential commands, organized logically to help you navigate the device's CLI efficiently. Remember that practice and familiarity with these commands will boost your confidence and reduce troubleshooting time. Always adhere to best practices, such as backing up configurations and testing changes in a controlled environment before deployment. With these tools and tips, you'll be well-equipped to manage Juniper devices with proficiency.

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Note: For more detailed command options and advanced configurations, refer to the official Juniper Networks Junos OS documentation and command references.