Juniper MX204 Setup Guide

Juniper MX204 is router from Juniper running Junipers own operation system Junos.

The MX204 has 4x 40Gb and 8x 10Gb. The 40Gb ports can be split into 4x 10Gb.

After unboxing it has no configuration. Connect a standard RS232 console cable with a Cisco style RJ45 connector, set your terminal to 9600 8N1 and power it up.

The Junos console welcomes you with a standard FreeBSD login.

Login in with “root” and no password.

Start the Junos CLI with “cli”

roo@:# cli
root>

This is the standard mode that you will reach later when configuring such device over a network connection (Telnet/SSH)

Like Cisco, Junos has two modes “standard” mode and “configure” mode:

root> configure
[edit]
root#

Different to Cisco, on Junos configuration changes are not active immediatly. You can configure different things in config mode and when you finished type “commit” to active changes or “exit” to discard your changes.

Here are some settings for the first setup:

# change root password
set system root-authentication plain-text-password
# add another user
set system login user USERNAME authentication plain-text-password
set system login user USERNAME class super-user
# set host name
set system host-name HOSTNAME
# set the managment IP for the “mgmt” port
set interfaces fxp0 unit 0 family inet address ADDRESS/PREFIX_LENGTH
# On Junos 18.2 the default setting for fxp0 is dhcp, deactivate dhcp
delete interfaces fxp0 unit 0 family inet dhcp
# Starting in Junos OS 17.3R1 you can seperate the mgmt interface from the default routing table
set system management-instance
set routing-instances mgmt_junos routing-option static route 0.0.0.0/0 next-hop MGMT_LAN_ROUTER
# activate ssh (and/or telnet)
set system services telnet
set system services ssh
# Junos 18.2 has auto software upgrade, deactivate it
delete chassis auto-image-upgrade
# active and save all changes
commit

You can list you current configuration with “show” inside and “show configuration” outside of configuration mode

Starting with 18R1 Juniper MX204 can mix 10G and 1G ports on the 8 SFP+ Ports.

You have to set the pic to per port mode with

set chassis fpc 0 pic 1 port 0 speed 10g
set chassis fpc 0 pic 1 port 1 speed 10g
set chassis fpc 0 pic 1 port 2 speed 10g
set chassis fpc 0 pic 1 port 3 speed 10g
set chassis fpc 0 pic 1 port 4 speed 10g
set chassis fpc 0 pic 1 port 5 speed 10g
set chassis fpc 0 pic 1 port 6 speed 10g
set chassis fpc 0 pic 1 port 7 speed 10g

# and
set interface xe-0/1/7 gigether-options speed 1g
# or
set interface xe-0/1/7 gigether-options speed 10g

If you like to backup the config to a server you can copy the config using ssh:

file copy /config/juniper.conf.gz configs@80.245.199.199:router.conf.gz

ToBeContinued