.qcow2 (QEMU Copy-On-Write), which is the standard format for KVM-based hypervisors used in EVE-NG and GNS3.
How to Legally Download vios-adventerprisek9-m.SPA.159-3.M6.qcow2
: Identify your specific Cisco device model. Cisco provides a search function or a list of products; select the one that matches your device.
: Support for MPLS L3VPN, L2VPN, and Traffic Engineering.