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Juniper vQFX#

Juniper vQFX virtualized router is identified with juniper_vqfx kind in the topology file. It is built using vrnetlab project and essentially is a Qemu VM packaged in a docker container format.


The public vQFX image that is downloadable from the Juniper portal mentions version 20.2, but in fact, it is a 19.4 system. Until this issue is fixed (and it seems no one cares), rename the downloaded qcow2 file to mention the 19.4 version before building the container image.

Managing Juniper vQFX nodes#


Containers with vQFX inside will take ~7min to fully boot.
You can monitor the progress with docker logs -f <container-name>.

Juniper vQFX node launched with containerlab can be managed via the following interfaces:

to connect to a bash shell of a running Juniper vQFX container:

docker exec -it <container-name/id> bash

to connect to the vQFX CLI (password admin@123)

ssh admin@<container-name/id>

Looking for contributions.


Default user credentials: admin:admin@123

Interfaces mapping#

  • eth0 - management interface connected to the containerlab management network
  • eth1 - first data interface, mapped to first data port of vQFX line card
  • eth2+ - second and subsequent data interface

When containerlab launches Juniper vQFX node, it will assign IPv4/6 address to the eth0 interface. These addresses can be used to reach management plane of the router.

Data interfaces eth1+ needs to be configured with IP addressing manually using CLI/management protocols.

Features and options#

Node configuration#

Juniper vQFX nodes come up with a basic configuration where only the control plane and line cards are provisioned, as well as the admin user with the provided password.

Startup configuration#

It is possible to make vQFX nodes boot up with a user-defined startup-config instead of a built-in one. With a startup-config property of the node/kind user sets the path to the config file that will be mounted to a container and used as a startup-config:

      kind: juniper_vqfx
      startup-config: myconfig.txt

With this knob containerlab is instructed to take a file myconfig.txt from the directory that hosts the topology file, and copy it to the lab directory for that specific node under the /config/startup-config.cfg name. Then the directory that hosts the startup-config dir is mounted to the container. This will result in this config being applied at startup by the node.

Configuration is applied after the node is started, thus it can contain partial configuration snippets that you desire to add on top of the default config that a node boots up with.

Lab examples#

Looking for contributions.