Vqfx-20.2r1.10-re-qemu.qcow2 [top]

To "make a piece" out of the vqfx-20.2R1.10-re-qemu.qcow2 image—the Routing Engine (RE) for the Juniper vQFX virtual switch—you generally need to integrate it into a network emulation environment like

Here is how to set it up as a functional "piece" of your lab: 1. The "Two-Piece" Requirement

The vQFX operates using a split architecture. To have a working switch, you must pair the RE image you have with a matching Packet Forwarding Engine (PFE) Routing Engine (RE): vqfx-20.2R1.10-re-qemu.qcow2 (Controls the device). Forwarding Engine (PFE): Typically named something like vqfx-20.2R1-2019010209-pfe-qemu.qcow (Handles the data traffic). 2. Common Integration Steps

Depending on your platform, use these steps to build the node: Navigate to Edit -> Preferences -> Qemu VMs Name the VM "vQFX-RE" and assign 1024 MB RAM Select your file as the disk image. The default credentials are typically In EVE-NG: Create a directory named /opt/unetlab/addons/qemu/vqfxre-20.2R1.10/ Upload the file into that directory and rename it to Fix permissions using the command: /opt/unetlab/wrappers/unl_wrapper -a fixpermissions In Cisco Modeling Labs (CML): Tools -> Node and Image Definitions

and import the appropriate YAML definition for Juniper vQFX. Upload your image and map it to the RE definition. 3. Critical Setup Tips Connectivity: You must connect the interface of the RE directly to the interface of the PFE for them to communicate. Proper Shutdown: Always use the command request system power-off

This file is a QEMU disk image for vQFX, which is the virtualized version of Juniper Networks' QFX Series switch. It is specifically the Routing Engine (RE) image.

4. Use Cases (2024/2025 Context)

Given the version is 20.2 (circa 2020), it is outdated for production but useful for:

⚠️ Important: The "Missing" Half

A vQFX requires two separate virtual machines to function. You have the RE (Control Plane), but you also need the vPFE (Packet Forwarding Engine) image. Vqfx-20.2r1.10-re-qemu.qcow2

Without the vPFE, the switch will boot, but it will not be able to forward traffic or bring up data ports.
You typically need a file named something like vqfx-20.2r1.10-pfe.qcow2 to pair with this RE image.

9. Security Note (Critical)

Do not expose the management interface of this image to the internet or untrusted networks. Version 20.2R1 has known unpatched CVEs (e.g., JSA11071, JSA11098). Always place it behind a firewall or in an isolated lab VLAN.

Summary: A functional but aged disk image for Juniper's virtual QFX switch. Useful for labs and certification practice, but obsolete for production. Requires a companion PFE image for actual packet forwarding.

Several helpful blog posts and guides cover the deployment and configuration of vQFX-20.2r1.10-re-qemu.qcow2, primarily focusing on network simulation environments like GNS3, Containerlab, and Cisco Modeling Labs (CML). Recommended Blog Posts & Guides

Juniper vQFX on GNS3 - Brezular's Blog: This detailed guide provides specific QEMU settings for the vqfx-20.2R1.10-re-qemu.qcow2 image. It covers assigning 1024 MB RAM, configuring two vCPUs, and changing the NIC type to virtio-net-pci to ensure the Packet Forwarding Engine (PFE) is recognized.

Juniper vQFX and Containerlab - The ASCII Construct: This blog post explores using Containerlab to spin up vQFX topologies. It walks through building Docker images from the vQFX qcow2 files and verifying the resulting topology.

Importing vQFX into CML 2.4 - Cisco Learning Network: A step-by-step tutorial for users looking to run Juniper images in a Cisco environment. It includes links to community-made node definitions specifically for these images.

vQFX on KVM/QEMU for Testing - GitHub Gist: A technical walkthrough that details using shell commands to get vQFX images running directly on KVM/QEMU, bypassing higher-level orchestrators if you prefer a manual setup. Key Configuration Tips

Hardware Requirements: For the Routing Engine (RE) VM, assign at least 1024 MB RAM and 2 vCPUs. To "make a piece" out of the vqfx-20

NIC Type: Ensure the NIC type is set to virtio-net-pci. Using the default Intel e1000 may prevent the RE from communicating correctly with the PFE.

Interface Connections: Connect the first interface (em0) to your management/admin network and the second interface (em1) directly to the PFE's second interface.

Graceful Shutdown: Always use the Junos command request system power-off before closing your lab software. Improperly powering off the VM can lead to file system corruption or the device failing to load properly on next boot.

Are you planning to run this image in GNS3, EVE-NG, or another specific lab environment? Juniper vQFX on GNS3 - Brezular's Blog

vqfx-20.2R1.10-re-qemu.qcow2 is a virtual disk image for the Routing Engine (RE) of a Juniper vQFX switch. Cisco Learning Network

To run a functional vQFX instance, you must pair this RE image with its corresponding Packet Forwarding Engine (PFE) image, typically named something like vqfx-20.2R1-2019010209-pfe-qemu.qcow Cisco Learning Network 1. Getting Started: Basic Requirements Virtualization Platforms: Commonly used in Cisco Modeling Labs (CML) Resources: Assign at least 1024 MB RAM for the RE node. Default Credentials: (case-sensitive). Cisco Learning Network 2. Setup and Connectivity

The vQFX requires a specific internal connection to bridge the control plane (RE) and data plane (PFE). Management Port: Connect the first interface ( ) of the RE to your management network or admin VLAN. Internal Link: Connect the second interface ( ) of the RE directly to the second interface ( ) of the PFE. Data Ports:

Your actual switch traffic (xe-0/0/x) is processed by the PFE, but configured via the RE. Cisco Learning Network 3. Common Setup Troubleshooting Guide: Importing Juniper vMX and vQFX into CML2.4 Without the vPFE, the switch will boot, but

vqfx-20.2R1.10-re-qemu.qcow2 Routing Engine (RE) disk image for the Juniper vQFX virtual switch. To use it effectively in a network lab (like GNS3, EVE-NG, or CML), it must be paired with a corresponding Packet Forwarding Engine (PFE) Technical Overview & Setup Guide 1. System Requirements Minimum 1024 MB RAM for the RE. Virtualization: Requires KVM/QEMU acceleration. Default Credentials: (Note: Capital 'J'). 2. Architecture & Connectivity

The vQFX operates as a split-VM system where the RE handles the control plane and the PFE handles the data plane. RE Interface em0: Management/Admin VLAN. RE Interface em1: Dedicated link to the PFE's em1 interface. Traffic Ports:

User-defined switch ports are typically presented on the RE but processed by the PFE. 3. Common Implementation Steps Import using the Juniper vQFX RE appliance file ). Assign the image to the QEMU VM configuration. In EVE-NG: Create a directory (e.g., /opt/unetlab/addons/qemu/vqfx-20.2R1.10/ ), rename the file to , and run the fixpermissions In Cisco CML: Import the node definitions and upload the via the Image Definitions tab. Known Issues & Troubleshooting Guide: Importing Juniper vMX and vQFX into CML2.4

The Verdict

Pros:

Production-stable Junos code in a VM.
Supports modern data center protocols.
QCOW2 format allows instant snapshots and minimal storage usage.

Cons:

No official support without a contract.
High memory footprint compared to container-based routers (like cRPD).
Not suitable for throughput testing (only control plane testing).

9. Alternatives & Related Images

| Image | Purpose | |-------|---------| | vqfx-20.2r1.10-pfe-qemu.qcow2 | Packet Forwarding Engine (required for switching/routing data) | | vqfx-20.2r1.10-veos (community) | Arista vEOS as L2 leaf (mixed-vendor lab) | | vjunos-switch-22.2R1.11.qcow2 | Newer vJunos-switch (unified RE+PFE) – simpler but heavier | | vqfx-10000-21.1R1-re-qemu.qcow2 | Updated version with better EVPN support |

5.1 In EVE-NG

Upload Vqfx-20.2r1.10-re-qemu.qcow2 to /opt/unetlab/addons/qemu/vqfx-20.2R1.10-re/
Rename it to hda.qcow2 (EVE-NG convention).
Fix permissions:
/opt/unetlab/wrappers/unl_wrapper -a fixpermissions
Add a vQFX RE node from the appliance list. Pair it with a vQFX PFE node.

Unpacking the Virtual Network Lab: A Deep Dive into `Vqfx-20.2r1.10-re-qemu.qcow2`

In the world of network engineering, the gap between theory and practice has traditionally been bridged by expensive hardware. For decades, mastering a platform like Juniper’s Junos OS meant investing in physical routing and switching platforms. However, the virtualization revolution has democratized network engineering. At the heart of this revolution for Juniper enthusiasts lies a specific, powerful file: Vqfx-20.2r1.10-re-qemu.qcow2.

This seemingly cryptic string represents a specific snapshot of Juniper’s virtualized data center switching platform. For students, DevOps engineers, and network architects, understanding what this file is, how to use it, and its specific version nuances is critical for building accurate, high-performance virtual labs.

This article will deconstruct the file name, explore its architecture, provide a setup guide, and discuss its role in modern network automation workflows.