If you have stumbled upon the filename vqfx202r110reqemuqcow2 work, you are likely deep in the trenches of network virtualization. This string is not random gibberish; it is a blueprint for a specific Juniper Networks virtual switch.
Let’s break it down:
This article explains exactly how to make vqfx202r110re-qemu.qcow2 work, from proper conversion to advanced troubleshooting.
Feature Name: Auto-provision + gRPC Telemetry Exporter
Target: vqfx202r110reqemuqcow2
Goal: When the vQFX boots, it:
If you want, I can:
To get the Juniper vQFX 20.2R1.10 (vqfx-20.2R1.10-re-qemu.qcow2) working correctly, you must pair it with its corresponding Packet Forwarding Engine (PFE) image. Unlike typical routers, the vQFX is a split-architecture virtual switch where the Routing Engine (RE) handles the control plane and the PFE handles the data plane. Core Components Required RE Image: vqfx-20.2R1.10-re-qemu.qcow2.
PFE Image: vqfx-20.2R1-2019010209-pfe-qemu.qcow (often bundled with the 20.2 download).
Note on Versioning: 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
The keyword vqfx202r110reqemuqcow2 refers to a specific virtual disk image file for the Juniper Networks vQFX virtual switch. Specifically, it represents the Routing Engine (RE) component of the vQFX, running Junos OS version 20.2R1.10 in a QEMU-compatible QCOW2 format. Understanding vQFX Architecture
To make this image "work," it is essential to understand that a vQFX instance requires two distinct virtual machines (VMs) running in tandem:
Routing Engine (RE): The control plane that runs the Junos OS and manages configuration.
Packet Forwarding Engine (PFE): The data plane (often referred to as the "Cosim" or PFE image) that handles actual traffic forwarding.
A common point of confusion is that the vqfx-20.2R1.10-re-qemu.qcow2 file downloaded from Juniper's portal has been reported by users to sometimes identify itself internally as version 19.4R1.10. Setting Up vQFX in Lab Environments
To deploy this image successfully in popular network simulators like GNS3 or EVE-NG, follow these core requirements: 1. Image Requirements and Resources vqfx202r110reqemuqcow2 work
RAM: 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.
Virtualization: KVM acceleration must be enabled on the host. 2. Critical Connectivity
The RE and PFE must be interconnected for the switch to function.
RE Interface em1 must connect directly to PFE Interface em1.
User-defined switch ports are typically mapped to the RE VM (unlike the vMX, where they map to the PFE). RE Interface em0 is used for the management/admin VLAN. 3. Deployment Steps (General) Juniper vQFX RE - GNS3
. This image is designed to run in a QEMU/KVM environment, often within network simulation platforms like
To get this specific image working, you typically need its counterpart, the PFE (Packet Forwarding Engine)
image, as the vQFX architecture splits these functions into two separate virtual machines. How to Get vQFX 20.2R1.10 Working
To successfully boot and use this image, follow these integration steps: Pair with the PFE : A vQFX setup requires two nodes. While your file is the RE (Control Plane) , you also need the corresponding vqfx-20.2R1.10-pfe-qemu.qcow2 Data Plane ) for traffic to actually flow. Resource Allocation RE (Your file) : Assign at least : Assign at least Connectivity : In your simulator (like EVE-NG), you must connect the interface of the RE to the
interface of the PFE. This internal link allows the "brain" (RE) to talk to the "muscle" (PFE). Management Access interface on the RE for SSH/Telnet management. Virtualization Settings Nested Virtualization
(VT-x/AMD-V) is enabled on your host machine, as Junos OS runs as a VM within QEMU. Common Troubleshooting Stuck at Boot
: If the RE hangs at the login prompt or doesn't see interfaces, ensure the PFE is powered on and the internal link is correctly mapped. License Warnings
: vQFX usually comes with a trial period. For lab use, "Evaluation" mode is standard, though some advanced features may require a license. QEMU Version QEMU 2.4.0 or higher for the best stability with Junos 20.x images. If you want, I can:
The request landed on Tariq’s terminal at 11:47 PM: REQ-VQFX-202-R110 / EMU / QCOW2.
He sighed. The lab’s physical switches were already racked and cabled for the new data center simulation, but the budget had been cut. Again. No hardware meant he had to build the entire spine-leaf topology in software.
"Alright, 'R110'," he muttered, pulling up the automation script. "Let's see if you work."
The vqfx202 was his go-to virtual switch—a tiny, fierce Juniper vQFX that acted like a 10-pound bruiser in a 1-pound sack. But the R110 requirement was the problem. The latest release. Buggy. Unforgiving.
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.
"Step one: clone," he whispered, typing:
qemu-img create -f qcow2 -b vqfx202-r110.qcow2 vqfx202-lab1.qcow2
The terminal blinked back: Formatting 'vqfx202-lab1.qcow2', fmt=qcow2 size=...
Good. The backing file was intact. He spun up the first emu instance—QEMU with PCI pass-through for the virtual ASICs.
qemu-system-x86_64 -machine pc -cpu host -smp 2 -m 4096 \
-drive file=vqfx202-lab1.qcow2,if=ide,index=1,media=disk \
-device virtio-net-pci,netdev=leaf1_int ...
The console flickered. Juniper’s loader chugged. Then—green text.
FreeBSD/x86 (vqfx202-re) (ttyu0)
He was in. The RE (Routing Engine) was alive.
"Ping the spine," he commanded the script. And silence.
No. Not silence—thundering quiet. The virtual links were down. He checked the bridge interfaces. The MACs were there. The VLAN tags matched. But the vqfx202 was stubborn as a mule. Then he smiled. Another impossible request
Then he remembered: the R110 release had a new quirk. It required explicit set chassis fpc 0 pic 0 tunnel-services for the virtual fabric links. The old R90 didn't need it.
He patched the configuration via netconf-console, holding his breath.
commit complete.
He launched a second emu instance—another leaf—and watched the LLDP neighbors crawl across the console like electronic ants.
System > vqfx202-re2 | Link: up | Protocol: up
"Work, you beautiful bastard," he grinned.
And it did. The tiny virtual spine saw the leaves. The leaves saw the hosts. Traffic flowed—not at 100G, but at virtual speed, enough for the devs to test their BGP policies.
At 2:13 AM, Tariq closed his laptop. The lab was running. 16 virtual switches, 32 host emulators, all eating RAM like candy, but holding steady.
He wrote in the handover log:
REQ-VQFX-202-R110 – Deployed. QCOW2 snapshots taken. EMU instances stable.
Note: tunnel-services required. Works. Barely. Don't touch until Monday.
Then he smiled. Another impossible request, shipped. Because at the end of the day, if you know how to bend QEMU, QCOW2, and Juniper’s will to your own… anything can work.
Run the modified image:
qemu-system-x86_64 -drive file=vqfx202r110reqemuqcow2,if=virtio \
-m 4096 -smp 2 -net user,hostfwd=tcp::2222-:22 -net nic \
-nographic -serial mon:stdio
Check:
ssh root@localhost -p 2222
show configuration services analytics