qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=2M vqfx202-prealloc.qcow2 8G
Powered by a companion image (typically named vqfx-20.2R1-2019010209-pfe-qemu.qcow or similar). This VM emulates the switching ASIC, handling packet forwarding, ACLs, and interface line-rate behaviors.
Once booted, you only configure the RE. If the VFP is running correctly, you should see the interfaces appear in Junos: vqfx202r110reqemuqcow2 top
Whether you are using GNS3 or EVE-NG, the core logic remains the same: the RE manages the control plane, while the PFE handles the data plane. 1. Image Requirements
If your 20.2 image shows as 19.4 after booting, this is a known issue with the Juniper download portal . If the VFP is running correctly, you should
The vQFX architecture splits the switch into two separate virtual machines:
:
To avoid common performance pitfalls, consider these two tips:
mkdir vqfxre-20.2R1.10 mkdir vqfxpfe-20.2R1 The vQFX architecture splits the switch into two
In the RES (Resident Memory) column, the image carves out its dedicated 2GB or 4GB of RAM, ensuring it has enough room to manage routing tables.
If you are running "top" (the Linux command) on your host server while this VM boots, you will notice the PFE image consumes the most CPU cycles during initialization as it initializes the virtual ASIC simulation.