Basic Operations #

Start the Junos OS CLI #

Log in as root
Start the CLI
```
root# cli
root@>
```
The > command prompt shows that you are in operational mode. Later, when you enter configuration mode, the prompt will change to #.

Type ? to show the top-level commands available in operational mode

root@> ?

Possible completions:
    clear           Clear information in the system
    configure       Manipulate software configuration information
    diagnose        Invoke diagnose script
    file            Perform file operations
    [...]

Methods to exit the paginated output

---(more ...%)--- q
% or
---(more ...%)--- <Ctrl+C>

Navigate Between OS Modes #

When you log in to the device and type the cli command and press Enter, you are automatically in operational mode
```
---JUNOS 17.2B1.8 built 2018-05-09 23:41:29 UTC
% cli
user@hostname>
```
To enter configuration mode, type the configure command or the edit command in CLI operational mode
```
user@hostname> configure
Entering configuration mode

[edit]
user@hostname#
```
You can exit configuration mode and return to operational mode in one of the following ways
```
[edit]
user@hostname# commit and-quit
% or
[edit]
user@hostname# exit
```
Use the run command to run operational mode commands whlie in configuration mode
```
[edit]
user@hostname# run <operational_mode_command>
```

Device Configuration #

Configure Hostname #

[edit]
root# set system host-name <hostname>

Configure Root Password #

[edit]
root# set system root-authentication plain-text-password
New password: **********
Retype new password: **********

Configure User Account #

Create the local user account

[edit]
root# set system login user <user> class super-user

Set the encrypted password

[edit]
root# set system login user <user> authentication plain-text-password
New password: **********
Retype new password: **********

Configure a Range of Interfaces #

user@hostname# wildcard range set interfaces ge-0/0/[<start>-<end>]

Delete Specific Configuration #

[edit]
user@hostname# delete <configuration_command>

SSH Configuration #

Configure hostname and domain name

user@hostname# set system host-name <hostname>
user@hostname# set system domain-name <domain_name>

Configure AES key pair

set system services ssh ciphers aes256-ctr
set system services ssh ciphers aes256-cbc
set system services ssh ciphers aes192-ctr
set system services ssh ciphers aes192-cbc
set system services ssh ciphers aes128-ctr
set system services ssh ciphers aes128-cbc

Allow users to login by SSH

user@hostname# set system services ssh protocol-version v2

Choose SSH version
```
user@hostname# set system services ssh
```

Verify and Monitor Juniper Device #

user@hostname> show configuration
user@hostname> show system commit
user@hostname> show interfaces
user@hostname> show arp
user@hostname> show version

Network Discovery #

Link Layer Discovery Protocol #

Enable LLDP globally

[edit]
user@hostname# set protocols lldp interface all

Enable LLDP for an interface

[edit]
user@hostname# set protocols lldp interface <interface>

Show all LLDP neighbors
```
user@hostname> show lldp neighbors
```

Device Management and Security #

Shut Down Unused Ports #

Identify unused ports
```
user@hostname> show interfaces terse
```

Shut down unused ports

[edit]
user@hostname# set interfaces <interface> disable

Upgrade the Switch #

Download the latest Junos OS image from Support - Juniper Networks

List the disks connected to your system

diskutil list

/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *500.3 GB   disk0
   1:             Apple_APFS_ISC Container disk1         524.3 MB   disk0s1
   2:                 Apple_APFS Container disk3         494.4 GB   disk0s2
   3:        Apple_APFS_Recovery Container disk2         5.4 GB     disk0s3

/dev/disk3 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +494.4 GB   disk3
                                 Physical Store disk0s2
   1:                APFS Volume Macintosh HD            10.7 GB    disk3s1
   2:              APFS Snapshot com.apple.os.update-... 10.7 GB    disk3s1s1
   3:                APFS Volume Preboot                 6.6 GB     disk3s2
   4:                APFS Volume Recovery                966.2 MB   disk3s3
   5:                APFS Volume Data                    141.3 GB   disk3s5
   6:                APFS Volume VM                      1.1 GB     disk3s6

/dev/disk4 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     FDisk_partition_scheme                        *8.1 GB     disk4
   1:               Windows_NTFS Untitled                8.1 GB     disk4s1

Unmount the USB drive
```
diskutil unmountDisk /dev/disk4
```
Write the Junos image to the USB drive
```
sudo dd if=junos-install-media-usb-ex-arm-32-21.4R3-S9.5.img of=/dev/rdisk4 bs=1m
```
Make sure to replace junos-install-media-usb-ex-arm-32-21.4R3-S9.5.img with the correct file path for your Junos image. Use /dev/rdisk4 instead of /dev/disk4 for faster write speeds on macOS.

Display the current configuration

cscc@twchou_J2300> show configuration | display set

Boot and install from USB

Boot Menu

1. Boot [P]revious installed Junos packages
2. Boot Junos in [S]ingle user mode
3. Boot from [R]ecovery snapshot
4. Boot from [U]SB
5. Boot to [O]AM shell
6. Snapshot [B]oot menu
7. [M]ain menu

Verify the installed version

--- JUNOS 21.4R3-S9.5 Kernel 32-bit  JNPR-12.1-20240304.935bb4f_buil
root@:RE:0% cli
{master:0}
root> show version

Configure additional settings

{master:0}
root> configure
Entering configuration mode

{master:0}[edit]
root# delete chassis auto-image-upgrade

{master:0}[edit]
root# set system root-authentication plain-text-password
New password:
Retype new password:

{master:0}[edit]
root# commit

Reset the Switch #

Revert a Juniper EX2300 switch to its factory-default configuration using the Factory Reset/Mode button.

Press the Factory Reset/Mode button for 10 seconds

The switch transitions into factory-default configuration, the console displays committing factory default configuration, and the Link/Activity LED on the RJ-45 network ports and the uplink ports is lit steadily in green color.
Press the Factory Reset/Mode button for 10 more seconds

The switch transitions into initial setup mode, the console displays committing ezsetup config, and the Link/Activity LED on the RJ-45 network ports and the uplink ports blink in green color.