Use tar xvf vmx-bundle-17.1R1.8.tgz to extract the contents.
Create the folder /opt/unetlab/addons/qemu/vmxvcp-17.1R1.8-domestic-VCP and copy junos-vmx-x86-64-17.1R1.8.qcow2 into it, renaming it to virtioa.qcow2 . verified download juniper vmxbundle 171r18tgz work
For Juniper Networks software, you can verify the authenticity of the download by: Use tar xvf vmx-bundle-17