Running the Juniper vQFX image vqfx-20.2R1.10-re-qemu.qcow2 requires understanding that vQFX operates as a split-brain system consisting of two separate virtual machines: the Routing Engine (RE) Packet Forwarding Engine (PFE) Cisco Learning Network Core Setup Requirements

Section 5: Advanced – Making It Work for EVPN-VXLAN Labs

The real value of getting this qcow2 to work is building multi-node topologies. Use libvirt networks to connect multiple vQFX instances.

Expected output:
file format: qcow2
virtual size: 4 GiB (4294967296 bytes)

Config Archiving: Since virtual disks can corrupt, always keep a backup of your set commands. Final Verdict

In the virtual workspace, the engineer placed both nodes. But they were deaf and blind until the Internal Link was forged. The em1 interface of the RE was wired directly to the eth1 of the PFE.