The screen went black for a heartbeat. Then, the rhythmic green pulse of the Universal Image took over. The "SPA" digital signature validated with a satisfying chime, signaling that the firmware was authentic and secure. "Cryptographic handshake complete," Elias breathed.
: It is enabled using the command configuration mode exclusive within the IOS CLI. Cross Platform Release Notes for Cisco IOS Release 15.7(3)M c800universalk9mzspa1573m9bin exclusive
Log into the router and verify current resources: The screen went black for a heartbeat