Cisco Catalyst 3560-X Series, Software Configuration Manual

Page: 1409 / 1538

1-29
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-25303-03
Chapter 1 Troubleshooting
Troubleshooting Tables
Troubleshooting Tables
These tables are a condensed version of troubleshooting documents on Cisco.com.
•
“Troubleshooting CPU Utilization” on page -29
• “Troubleshooting Power over Ethernet (PoE)” on page -31
•
“Troubleshooting Stackwise (Catalyst 3750-X Switches Only)” on page -34
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.
Table 1-5 lists the primary types of CPU utilization problems
that you can identify. It gives possible causes and corrective action with links to the Troubleshooting
High CPU Utilization document on Cisco.com.
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.
• 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:
Note
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
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.
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