They require specific virtio drivers. Always use EVE-NG community-recommended images (e.g., vios-adventerprisek9-m-15.2.qcow2 ).
md5sum /opt/unetlab/addons/qemu/iosv-17.13.01/virtioa.qcow2 # Compare with the vendor’s published MD5
Let’s assume you downloaded (a Cisco IOSv image). Here’s how to make it work.
Download directly from vendors like Cisco , Fortinet , or Palo Alto .