SystemPrivileged EXEC

show processes cpu

Displays CPU utilization statistics for all processes running on the Cisco IOS device, used to identify processes consuming excessive CPU and diagnose performance issues.

Syntax·Privileged EXEC

show processes cpu

When to Use This Command

Troubleshooting high CPU utilization causing network latency or packet drops.
Identifying a specific process (e.g., routing protocol, SNMP) that is consuming excessive CPU cycles.
Monitoring CPU usage over time to detect abnormal spikes or gradual increases.
Verifying the impact of configuration changes or new features on CPU performance.

Command Examples

Basic CPU utilization overview

show processes cpu

CPU utilization for five seconds: 8%/2%; one minute: 7%; five minutes: 6%
 PID  Runtime(ms)  Invoked      uSecs   5Sec   1Min   5Min  TTY  Process
   1           0          1          0  0.00%  0.00%  0.00%    0  Chunk Manager
   2        1234       5678        217  0.20%  0.15%  0.12%    0  Load Meter
   3           0          2          0  0.00%  0.00%  0.00%    0  OSPF Hello
   4       56789      12345       4599  5.00%  4.50%  4.00%    0  IP Input
   5         100        200        500  0.01%  0.01%  0.01%    0  ARP Input
   6        5000       1000       5000  0.50%  0.40%  0.35%    0  SNMP Engine

First line shows overall CPU utilization: 8% total, 2% interrupt overhead. '5Sec', '1Min', '5Min' columns show per-process CPU usage over those intervals. 'Runtime(ms)' is total CPU time used since boot, 'Invoked' is number of times process ran, 'uSecs' is average microseconds per invocation. High '5Sec' values indicate current CPU hogs.

Sorting by CPU utilization

show processes cpu | include ^CPU|IP Input|OSPF|BGP

CPU utilization for five seconds: 45%/5%; one minute: 40%; five minutes: 35%
   4      567890     123456       4599 25.00% 22.00% 20.00%    0  IP Input
   7      123456      78901       1567 10.00%  8.00%  7.00%    0  OSPF Router
   8      234567      34567       6789  5.00%  4.00%  3.00%    0  BGP Router

Filtered output shows only processes of interest. High CPU in IP Input may indicate traffic spikes or attacks; OSPF/BGP high CPU could mean route flapping or neighbor issues.

Understanding the Output

The first line shows overall CPU utilization: 'five seconds' is the current snapshot (total%/interrupt%), 'one minute' and 'five minutes' are rolling averages. The table lists each process with PID, runtime (total CPU time in milliseconds since boot), invoked count, average microseconds per invocation, and CPU percentages over 5 seconds, 1 minute, and 5 minutes. TTY column shows terminal association (0 for system processes). High '5Sec' values (e.g., >50%) indicate immediate CPU hogs; sustained high '1Min' or '5Min' suggest chronic issues. Watch for processes like 'IP Input' (high traffic), routing protocols (flapping), or 'SNMP Engine' (excessive polling). Interrupt overhead (second percentage in first line) above 10% may indicate hardware issues or high packet rates.

CCNA Exam Tips

CCNA exam may ask which process is causing high CPU; look for 'IP Input' or routing protocol processes.

Remember that the first line shows total CPU and interrupt overhead; interrupt overhead above 10% often indicates a hardware or Layer 1 issue.

The '5Sec' column is the most immediate indicator of current CPU usage; '1Min' and '5Min' show trends.

Know that 'show processes cpu' is used for real-time troubleshooting, while 'show processes cpu history' shows graphical historical data.

Common Mistakes

Mistake 1: Confusing total CPU with interrupt overhead; the first line shows 'total%/interrupt%'.

Mistake 2: Ignoring the '5Min' column; a process with high '5Sec' but low '5Min' may be a transient spike.

Mistake 3: Using this command without filtering when looking for a specific process; use '| include' to narrow down.

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