Cisco Systems 3560X Manual De Usuario

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. 

 lists the primary types of CPU utilization problems 

that you can identify. It gives possible causes and corrective action with links to the 

 

document on Cisco.com.

Note that excessive CPU utilization might result in these symptoms, but the symptoms could also result 
from other causes.

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 switches:

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 

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.

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>

This example shows normal CPU utilization. The output shows that utilization for the last 5 seconds is 
8%/0%

, which has this meaning:

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.