Troubleshooting Cpu Utilization; Possible Symptoms Of High Cpu Utilization; Verifying The Problem And Cause - Cisco Catalyst 3750-X Software Configuration Manual

Troubleshooting Tables

Troubleshooting CPU Utilization

This section lists some possible symptoms that could be caused by the CPU being too busy and shows
how to verify a CPU utilization problem.
that you can identify. It gives possible causes and corrective action with links to the
High CPU Utilization

Possible Symptoms of High CPU Utilization

Note that excessive CPU utilization might result in these symptoms, but the symptoms could also result
from other causes.
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Layer 3 switches:
Note
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Verifying the Problem and Cause

To determine if high CPU utilization is a problem, enter the show processes cpu sorted privileged
EXEC command. Note the underlined information in the first line of the output example.
This example shows normal CPU utilization. The output shows that utilization for the last 5 seconds is
8%/0%, which has this meaning:
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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
51-28
document on Cisco.com.
Spanning tree topology changes
EtherChannel links brought down due to loss of communication
Failure to respond to management requests (ICMP ping, SNMP timeouts, slow Telnet or SSH
sessions)
UDLD flapping
IP SLAs failures because of SLAs responses beyond an acceptable threshold
DHCP or IEEE 802.1x failures if the switch does not forward or respond to requests
Layer 3 functions are not supported on switches running the LAN base feature set.
Dropped packets or increased latency for packets routed in software
BGP or OSPF routing topology changes
HSRP flapping
Switch# show processes cpu sorted
CPU utilization for five seconds: 8%/0%; one minute: 7%; five minutes: 8%
PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process
309 42289103 752750 56180 1.75% 1.20% 1.22% 0 RIP Timers
140 8820183 4942081 1784 0.63% 0.37% 0.30% 0 HRPC qos request
100 3427318 16150534 212 0.47% 0.14% 0.11% 0 HRPC pm-counters
192 3093252 14081112 219 0.31% 0.14% 0.11% 0 Spanning Tree
143 8 37 216 0.15% 0.01% 0.00% 0 Exec
...
<output truncated>
The total CPU utilization is 8 percent, including both time running Cisco IOS processes and time
spent handling interrupts
The time spent handling interrupts is zero percent.
Table 51-4 lists the primary types of CPU utilization problems
Chapter 51 Troubleshooting
Troubleshooting
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