Cisco ISR4321/K9 V04 Integrated Services Router w/ UC License, NO CPU CLOCK BUG | eBay
A Rare Peek Inside A 400G Cisco Network Chip
GitHub - uptimesoftware/cisco-router-cpu-mem-monitor: Monitor Cisco Router CPU and Memory. This can be done up.time 7+ with the built-in SNMP Poller monitor.