Configuring Juniper QFX5100

For example, I will configure the Juniper QFX5100-24Q-AFO switch.

When connected with a console cable, the default speed is 9600, the user is root without a password.

Disable automatic software updates as I described in the article and specify the root password for the user:
Solution of failing auto-image upgrade

Let’s switch to CLI mode:


Let’s see the current device parameters:

show chassis hardware
show chassis fpc
show chassis fpc 0 detail
show chassis pic fpc-slot 0 pic-slot 0
show interfaces
show interfaces ?

An example of viewing DDM information on an optical module:

show interfaces diagnostics optics et-0/0/0

Let’s go to configuration mode:


Set up SSH and Telnet if necessary:

set system services ssh
set system services ssh port 2222
run show system connections extensive | match "22|2222" | match LISTEN
set system services telnet
show system services

Let’s add an administrator who will connect via SSH or Telnet (I note that the root user cannot connect):

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

Set up time synchronization:

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

arp records storage time in minutes:

set system arp aging-timer 5

Set up SNMP:

set snmp community IXNFO.COM clients

An example of viewing logs:

show log ?
show log messages | last 50
show log user | last 50
show log chassisd | last 50
show log chassisd_snmp | last 50
show log cosd | last 50
show log interactive-commands | last 50
show log jddosd | last 50

show log dhcp_logfile | last 50
file list /var/log/
file delete /var/log/dhcp_logfile

Let’s create the necessary vlan lists (using the example, I created users and core):

set vlans users vlan-id-list [226-228 301-302 501 599-612 700-776 778-800 943-1001 1050-1060]
set vlans core vlan-id 500
run show vlans

I will give an example of configuring the Trunk port (in order not to list vlan, you can specify the names of the vlan lists):

set interface et-0/0/7 vlan-tagging
set interface et-0/0/7 unit 0 family ethernet-switching interface-mode trunk
set interface et-0/0/7 unit 0 family ethernet-switching vlan members [ core users ]
edit interface et-0/0/7
set description UPLINK
set interface et-0/0/8 vlan-tagging
set interface et-0/0/8 unit 0 family ethernet-switching interface-mode trunk
set interface et-0/0/8 unit 0 family ethernet-switching vlan members users

An example of changing the MTU:

set interfaces et-0/0/7 mtu 9216

Example of setting up an ACCESS port:

interfaces {
    et-0/0/0 {
        unit 0 {
            family ethernet-switching {
                interface-mode access;
                vlan {
                    members 777;

For mass configuration, you can use the “wildcard” command, for example, remove the xe-0/0/9:0-3 interfaces, as well as xe-0/0/0-23:

edit interfaces
wildcard range delete xe-0/0/9:[0-3]
wildcard range delete xe-0/0/[0-23]:[0-3]

Another example:

wildcard range set interfaces et-0/0/[8-9] unit 0 family ethernet switching

Let’s configure the management port em0 (C0), the switch also has an SFP port C1 for management:

edit interfaces em0
set unit 0 family inet address
set routing-options static route default next-hop

Check and apply the configuration (at this point, the connection will be lost for about 1 second):

commit check
commit confirmed 1

I will give examples of viewing the MAC address table:

run show ethernet-switching table
show ethernet-switching table vlan-id 220
show ethernet-switching table 3c:fd:00:bb:7f:00

View statistics:

show chassis routing-engine
show system processes extensive

See also my articles:

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