Juniper MX204 setup

In this article I will give an example of configuring Juniper MX204, other Juniper MX series (JunOS) can be configured in the same way.

Connect to the device with a console cable and launch the Command Line Interface (CLI):


By default, the login is root without a password.

Let’s see the current configuration:

show configuration

Let’s see information about components, CPU and memory usage, temperature, JunOS version, etc.

show chassis hardware
show chassis routing-engine
show system memory
show system storage
show chassis environment
show version
show system information

A few more examples of commands for viewing other information:

show system alarms
show system uptime
show system connections
show system errors active
show system users
show system resource-monitor summary
show system processes extensive
show subscribers summary
show subscribers extensive
show bridge mac-table

Let’s go to configuration:


To execute CLI commands without returning to the CLI, add “run” before the command, for example:

run show configuration

Specify the password for the root user (after entering the command, you will need to enter the password):

set system root-authentication plain-text-password

Let’s create a new user admin (for example, we will use this user to connect via SSH in the future):

set system login user admin authentication plain-text-password
set system login user admin class super-user

set system login user admin class ?
operator        permissions [ clear network reset trace view ]
read-only       permissions [ view ]
super-user      permissions [ all ]
unauthorized    permissions [ none ]

Let’s specify the hostname:

set system host-name "test"
set system domain-name ""

Assign an IP address for the Ethernet management port (we will connect the cable to it later), and also indicate the DNS server and default route:

set interfaces fxp0 unit 0 family inet address
set system name-server
set routing-options static route next-hop
run show route

To apply any changes to the configuration, you must run the “commit” command, for example, check the configuration and apply:

commit check
commit ?

You can undo the changes made with the rollback 0 command, or you can revert the older configuration:

run show system commit
rollback ?
rollback 0
rollback 1

Let’s check the connection with the ping command:

run ping

Let’s see the configuration of network interfaces:

edit interfaces

fxp0 {
    unit 0 {
        family inet {

I will give an example of deleting a command, for example, delete the IP address and apply the changes:

delete fxp0 unit 0 family inet address

We activate ssh or telnet:

set system services ssh
set system services telnet
show system services

You can see who else is editing the configuration with the command:


Let’s set the time:

set system ntp server
set system time-zone Europe/Kiev

An example of resetting settings and completely clearing the configuration, log files and other things:

load factory defaults
request system zeroize

Examples of viewing logs:

show log messages | last 30
show log messages | match "Dec 27 10:30"
show log messages | match "Error"
show log messages | match "Error" | last 10
show log cli-comands | last 30
show log user admin
show log ?
show system alarms
show system boot-messages

Reboot device:

request system reboot

See also my articles:
Configuring SNMP
Configuring NTP
Restricting access to management
Juniper MX configuration backup

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