Vqfx202r110reqemuqcow2 Exclusive Jun 2026

Standard vQFX does not support Virtual Chassis Fabric (VCF). However, some exclusive builds have patched vcp interfaces. Check for vcp-0/0/0 :

extension makes it natively compatible with KVM/QEMU, supporting features like thin provisioning and snapshots, which are essential for lab scalability. Version Note

To build stable labs with these exclusive images, adhere to these architectural rules:

Once wrapped, launching an exclusive vQFX instance inside a container infrastructure becomes as straightforward as defining a YAML block: vqfx202r110reqemuqcow2 exclusive

: Despite the "20.2R1.10" label in the filename, many users have reported that the official Juniper evaluation download for this version actually runs Junos 19.4R1 internally. Requirements : RAM : Typically requires 1024 MB for the RE.

Move your file into this directory and rename it exactly to virtioa.qcow2 :

The RE needs at least two network interfaces: one for out-of-band management (fxp0) and one to talk exclusively to its twin Forwarding Engine. Standard vQFX does not support Virtual Chassis Fabric (VCF)

Keeps OSPF, BGP, and RSVP timers precise.

: The vQFX requires two separate virtual machines to function: this RE image for the control plane and a corresponding PFE (Packet Forwarding Engine) image for the data plane. Image Format

The vQFX RE image defaults to expecting a serial console. If your hypervisor fails to display output after the initial GRUB bootloader menu, ensure your QEMU execution string includes the -serial mon:stdio argument and flags -nographic . 2. Mitigating High CPU Usage on Host Version Note To build stable labs with these

If you are trying to build a lab:

Why is this particular release sought after? Version 20.2R1 is considered a "goldilocks" release for vQFX. It stabilized EVPN multihoming (ESI-LAG) and VXLAN routing, while later versions (20.4+) introduced resource bloat that broke many QEMU/KVM setups. The build is known for its lean memory footprint (~4GB RAM) and stable PCIe passthrough.

You can use virt-install to create a VM from the qcow2 image:

A KVM-enabled host (Ubuntu 22.04/24.04 recommended) or GNS3 VM. The vqfx-20.2R1.10-re-qemu.qcow2 image file. A corresponding PFE image. 2. Deployment Steps