sudo qemu-nbd --connect=/dev/nbd0 csr1000v-ucmk9.16.12.1b-serial.qcow2

The is a staple for any network professional’s toolkit. Whether you are studying for your CCNA, CCNP, or CCIE, having a stable, serial-enabled QCOW2 image allows you to practice advanced routing and automation scripts in a safe, virtualized environment.