Legacy .bin files allowed routing protocol processes (OSPF, IS-IS) to consume up to 95% CPU. The QCOW2 overlay enforces a cgroup limit, capping control-plane CPU at 75% during route flapping. This keeps SSH and SNMP responsive.
As a QCOW2 image, this firmware supports live snapshots. You can now perform an in-service software upgrade (ISSU) and take a copy-on-write delta before commit. If the new features fail, revert in under 300ms. Traditional firmware requires a 5-minute reboot. ne40ev800r011c00spc607b607qcow2 better