Vqfx-20.2r1.10-re-qemu.qcow2 May 2026

This looks like a QEMU disk image filename for a virtual network device, specifically a vQFX (virtualized Juniper QFX Series switch).

Let’s break it down:

  • vQFX – Virtualized version of Juniper’s QFX switch (used for data center switching/VXLAN/EVPN).
  • 20.2R1.10 – JunOS version (release 20.2, first maintenance release, build 10).
  • re – Likely stands for Routing Engine (the control plane component).
  • qemu – Means it’s intended to run under QEMU/KVM (not VMware).
  • qcow2 – QEMU’s copy-on-write disk image format.

Typical use:
Running a Juniper vQFX virtual switch in a lab (e.g., using libvirt, virt-manager, or devices.vqfx in vrnetlab / containerlab).

If you’re trying to use it:

  • Check memory/CPU requirements (vQFX needs 8GB+ RAM for RE + PFE).
  • Needs KVM acceleration for decent performance.
  • Default login is usually root with no password (or root / root).

Would you like help with converting it to another format, launching it in QEMU, or integrating it into a network lab?

Known Working Environments

  • ✅ EVE-NG (Community & Pro) – Recommended for dual-node setups.
  • ✅ GNS3 (with QEMU appliance template)
  • ✅ Ubuntu 20.04/22.04 with qemu-system-x86_64
  • ⚠️ VMware ESXi – Requires conversion to .vmdk and often lacks PFE performance.

5.2 Manual QEMU Command (RE only – no data plane)

qemu-system-x86_64 -machine pc -cpu host -smp 2 -m 4096 \
  -drive file=Vqfx-20.2r1.10-re-qemu.qcow2,if=ide,index=0,media=disk \
  -serial telnet:127.0.0.1:5000,server,nowait -nographic

Step 5: Initial Login

Once booted (wait ~2-3 minutes for the first boot), log in via the VNC console or virsh console vqfx-leaf1.

  • Login: root
  • Password: (None – press Enter)
  • Run cli to enter Junos command line.
  • Run configure to set a root password and commit.

Example Python Code with Libvirt

from libvirt import open
import os
# Open the connection
conn = open('qemu:///system')
# Get the domain (VM) by name
dom = conn.lookupByName('your_vm_name')
# Start the VM
dom.create()
# ... other operations ...
# Close the connection
conn.close()

If you have a more specific feature in mind, such as automation of certain tasks, performance enhancements, or integration with other tools, please provide more details to get a more targeted response.

This guide covers the vqfx-20.2R1.10-re-qemu.qcow2 image, which is the Routing Engine (RE) component of the Juniper vQFX virtual switch. It is typically used alongside the PFE (Packet Forwarding Engine) image to simulate Juniper QFX switches in virtual environments like GNS3 or Cisco CML. Key Information & Usage Purpose: Juniper Virtual QFX Switch Routing Engine.

Required Images: To function, this RE image must be paired with a corresponding PFE image (e.g., vqfx-20.2R1-2019010209-pfe-qemu.qcow).

Default Credentials: Username root, Password Juniper (capital J). RAM Requirement: 1024 MB.

Required Connection: Connect the em1 interface of the RE (vqfx-20.2R1.10-re-qemu.qcow2) directly to the em1 interface of the PFE node for management communication. Installation & Deployment Steps (GNS3)

Create VM: In GNS3, navigate to Preferences > QEMU VMs and click New.

Name & Memory: Name it (e.g., vQFX-RE) and assign 1024 MB RAM.

Image Selection: Choose the vqfx-20.2R1.10-re-qemu.qcow2 file as the disk image.

Pair PFE: After creating both RE and PFE nodes, ensure they are connected via their em1 interfaces.

Shutdown: Use request system power-off both-routing-engines inside JunOS to avoid boot issues in future sessions. Common Issues

"Non-master role" Warning: If the switch says it is in a "non-master role," it is likely a startup timing issue, and a manual reboot (request system reboot both-routing-engines) is often required.

Virtual Chassis: Ensure the RE and PFE properly synchronize; connecting em1 to em1 is critical. To help you further, please let me know: Are you using GNS3, CML, or Containerlab?

Do you have the corresponding PFE image (...pfe-qemu.qcow) ready? Vqfx-20.2r1.10-re-qemu.qcow2

I can provide specific configuration steps for your environment. Guide: Importing Juniper vMX and vQFX into CML2.4

The file vqfx-20.2r1.10-re-qemu.qcow2 is a virtual disk image representing the Routing Engine (RE) component of Juniper Networks' vQFX10000 virtual switch. This specific image is based on Junos OS 20.2R1 and is designed to run in a QEMU/KVM hypervisor environment, commonly used for high-fidelity network simulation in labs like GNS3 or EVE-NG. Key Technical Architecture

To function as a complete switch, this RE image must be paired with a separate Packet Forwarding Engine (PFE) image (e.g., vqfx-20.2R1-2019010209-pfe-qemu.qcow).

Routing Engine (RE): Handles the control plane, including routing protocols (BGP, OSPF), management (SSH, SNMP), and the Junos CLI.

Packet Forwarding Engine (PFE): Handles the data plane, performing the actual packet switching and forwarding logic.

The Internal Link: The two virtual machines must be connected via their em1 interfaces to form a single functional switch unit. Known Issues & Version Discrepancies

A widely documented quirk of this specific evaluation image is that while the filename indicates version 20.2, the internal software often reports as 19.4R1.10 upon booting and running show version. Hostname: Defaults to vqfx-re.

Credentials: Default username is root with password Juniper (case-sensitive) or sometimes admin with admin@123 depending on the lab distribution. Lab Specifications

For stable operation in a virtual environment, follow these recommended resource allocations: Guide: Importing Juniper vMX and vQFX into CML2.4

A white paper or technical guide for the vqfx-20.2r1.10-re-qemu.qcow2 image would focus on its role as the Routing Engine (RE) component of Juniper's virtualized QFX10000 switch series. This image is designed for network emulation platforms like GNS3 and Containerlab to simulate complex Data Center (DC) fabrics. Technical Overview: Juniper vQFX 20.2R1.10

The vQFX is a split-architecture virtual machine consisting of two distinct parts:

Routing Engine (RE): The vqfx-20.2R1.10-re-qemu.qcow2 file serves as the control plane, running Junos OS. It handles management, routing protocols (BGP, OSPF, EVPN/VXLAN), and configuration.

Packet Forwarding Engine (PFE): A separate image (often named vqfx-20.2R1-pfe-qemu.qcow2) that acts as the data plane, performing the actual packet switching and forwarding. Deployment & Requirements

For stable operation in virtual environments, the following specifications are typically recommended:

Resources: Assign a minimum of 1024 MB RAM and 1 vCPU to the RE virtual machine.

Format: The .qcow2 format is natively supported by QEMU/KVM, making it compatible with GNS3, EVE-NG, and standard Linux virtualization tools. Initial Credentials: Username: root Password: Juniper (Note: The password is case-sensitive). Known Issues & Versions

Users have reported discrepancies where images labeled as 20.2 may actually identify as 19.4R1.10 after installation. To ensure you receive the correct 20.2R1 release, it is recommended to download from the "Application Package" section on the Juniper Support portal rather than "Application Media". Use Cases

Data Center Emulation: Testing EVPN/VXLAN designs and Spine-Leaf architectures without physical hardware. This looks like a QEMU disk image filename

CI/CD Pipelines: Using tools like vrnetlab to integrate Junos testing into automated network workflows.

Certification Study: Preparation for JNCIP or JNCIE-DC exams using a lightweight, virtualized environment. AI responses may include mistakes. Learn more download for vQFX 20.2 is actually 19.4 | Data Center

vqfx-20.2R1.10-re-qemu.qcow2 file is the Routing Engine (RE) disk image for the Juniper vQFX10000

, a virtualized version of the physical QFX10000 data center switch

. It handles the control plane functions, while a separate Packet Forwarding Engine (PFE) image handles the data plane. Cisco Learning Network Key Specifications Junos OS 20.2R1.10. File Size: Approximately 675 MB. MD5 Checksum: 20220bfa3d387184fce957936eeeb4ec Recommended RAM: Recommended CPUs: 1 or 2 vCPUs. Disk Interface: IDE or Virtio. Configuration & Setup

To "put together" a working vQFX node, you must link the RE to a PFE instance (e.g., vqfx-20.2R1-2019010209-pfe-qemu.qcow Cisco Learning Network Management Port ( Connect this to your management network or admin VLAN. Internal Link ( You must connect this interface directly to the PFE's

interface to establish the internal control link between the two VMs. Switch Ports:

In this virtual architecture, the logical switch ports are actually configured on the RE, but traffic is processed by the PFE. Default Credentials: (Note: the password is case-sensitive with a capital 'J'). Cisco Learning Network Supported Platforms

format is optimized for QEMU-based environments, making it compatible with: Available via the Juniper vQFX RE appliance in the GNS3 Marketplace. Cisco CML: Can be imported using community node definitions. KVM/Libvirt:

Can be manually installed on Linux servers for testing and QA. Cisco Learning Network Guide: Importing Juniper vMX and vQFX into CML2.4

The file vqfx-20.2r1.10-re-qemu.qcow2 is a virtual disk image for the Routing Engine (RE) of a Juniper vQFX virtual switch. It is used in network simulation environments like GNS3, Cisco Modeling Labs (CML), and EVE-NG. Key Specifications Device Type: Virtual Juniper QFX10000 series switch.

Component: Routing Engine (Control Plane). It must be paired with a separate Packet Forwarding Engine (PFE) image (e.g., vqfx-20.2R1-2019010209-pfe-qemu.qcow) to function as a complete switch. Version: Junos OS 20.2R1.10.

Format: .qcow2 (QEMU Copy-On-Write), standard for KVM-based hypervisors. Typical Setup Requirements

Memory: 1024 MB RAM is generally recommended for the RE instance. Default Credentials: Username: root Password: Juniper (Note: the "J" is usually capitalized).

Connectivity: In simulation tools, you typically connect the em1 interface of the RE directly to the em1 interface of the PFE for internal communication. Common Usage Issues

Rebooting: To avoid corruption of the live file system, always use the command request system power-off both-routing-engines (or halt) before shutting down the VM.

Non-Master Role: If the RE starts in a "non-master" role, a common workaround is to use the command request virtual-chassis reactivate or reboot both the RE and PFE simultaneously. Guide: Importing Juniper vMX and vQFX into CML2.4

Junos vQFX10000 is a virtualized version of the physical QFX10000 switch, designed for network simulation, lab testing, and automation development. The specific image file Vqfx-20.2r1.10-re-qemu.qcow2 represents the Routing Engine (RE) portion of this virtual switch for version 20.2R1.10, formatted for QEMU-based hypervisors. Understanding the vQFX Architecture vQFX – Virtualized version of Juniper’s QFX switch

Unlike a single-file virtual machine, the vQFX typically operates using a dual-VM architecture to simulate the high-performance hardware of the QFX series:

Routing Engine (RE): Handles the control plane, running Junos OS. This is what the Vqfx-20.2r1.10-re-qemu.qcow2 file powers.

Packet Forwarding Engine (PFE): Handles the data plane (transit traffic).

Communication: The RE and PFE connect via an internal bridge to function as a single logical switch. Key Technical Specifications Image Details Filename: Vqfx-20.2r1.10-re-qemu.qcow2 Junos Version: 20.2R1.10 Format: QCOW2 (QEMU Copy-On-Write) Primary Role: Control Plane / Management Recommended Resource Allocation (Per RE Instance) vCPU: 1 to 2 Cores RAM: 2 GB to 4 GB Disk Space: ~5 GB (Expanding) Deployment and Use Cases 1. Network Simulation (GNS3, EVE-NG, PNETLab)

This image is a staple for network engineers using emulation platforms. It allows for building complex data center topologies (like Leaf-Spine architectures) without needing physical hardware that costs thousands of dollars. 2. CI/CD and Automation Testing

Because it runs authentic Junos code, developers can use this image to: Validate Ansible playbooks. Test Python/PyEZ scripts.

Verify NETCONF/REST API calls against a live Junos interface. 3. Certification Preparation

It is an essential tool for candidates studying for Juniper certifications, specifically: JNCIS-ENT / JNCIP-ENT (Enterprise Routing and Switching) JNCIS-DC / JNCIP-DC (Data Center) Installation Quick-Start (General QEMU)

To run the RE image manually via QEMU, you would typically use a command similar to this:

qemu-system-x86_64 -m 2048 -hda Vqfx-20.2r1.10-re-qemu.qcow2 -net nic -net user

Note: For a functional switch, you must also link this instance to a corresponding PFE instance. Benefits of the 20.2R1.10 Release

Version 20.2 introduced several stability fixes and features for the QFX virtual line, including: Enhanced EVPN-VXLAN support for data center overlays.

Improved convergence times for routing protocols like BGP and OSPF.

Refined telemetry capabilities for modern network monitoring.

💡 Pro-Tip: When setting up vQFX in EVE-NG or GNS3, ensure you use the "virtio-net-pci" adapter type for the best performance and compatibility between the RE and PFE.

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.

2. File Characteristics

| Attribute | Value | |-----------|-------| | Filename | Vqfx-20.2r1.10-re-qemu.qcow2 | | Software Family | Juniper vQFX (Virtual QFX) | | JunOS Version | 20.2R1.10 | | Function | Control Plane (Routing Engine) | | Disk Format | qcow2 (QEMU) | | Typical Size | ~1–2 GB (sparse) | | Platform Emulated | QFX10000-36Q or QFX5110 (depending on VM config) |

Step 1: Prepare the Files

Ensure you have both the RE and PFE images.

  1. Vqfx-20.2r1.10-re-qemu.qcow2 (The file you have).
  2. vqfx-20.2r1.10-pfe.qcow2 (Required companion).