He downloaded the vqfx202-r110.qcow2 image—the golden QEMU copy-on-write file. It was pristine. Untouched. He’d learned long ago never to trust the raw images.
Assign at least 1024 MB (GNS3) to 2048 MB (EVE-NG) for the RE. The PFE typically requires more, up to 4096 MB in some configurations. CPU: 1-2 vCPUs.
Increase the RE RAM allocation to 3GB during the first boot sequence. Config Synchronization Fails
A unique aspect of the vQFX platform is its two‑VM architecture that mirrors a physical switch:
Below is a comprehensive technical guide on how this image works, how to deploy it, and how to troubleshoot common issues. What is the vQFX 20.2R1.10 RE Image?
Assuming you have downloaded the file vqfx202r110reqemuqcow2 (likely from a Juniper account or community lab source), follow these phases.
packages vQFX in a Docker container using the vrnetlab project, allowing you to launch Juniper vQFX nodes with a simple YAML file:
Even if the filename says 20.2, running show version within Junos may report 19.4R1 . This is a known labeling discrepancy from the Juniper portal. Basic Configuration Steps Guide: Importing Juniper vMX and vQFX into CML2.4
You should see Juniper bootloader (GRUB) output. If the system hangs at “Loading initrd…” — the image is either corrupted or the VM lacks sufficient RAM/CPU.
The first interface ( em0 / fxp0 in Junos) maps to your management network.
Linux-based KVM/QEMU installed ( qemu-kvm , libvirt-daemon-system ).
This article provides a comprehensive, step-by-step guide to downloading, configuring, and booting the Juniper vQFX 20.2R1 RE image. 1. Prerequisites for Running vQFX 20.2R1
The image file . Getting this specific image to work reliably requires understanding Juniper's split-architecture design, applying exact resource configurations, and mapping virtual interfaces precisely within a QEMU-based hypervisor environment like GNS3, EVE-NG, Cisco Modeling Labs (CML), or Containerlab.