Cisco Systems 3560X Manual De Usuario
51-29
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 51 Troubleshooting
Troubleshooting Tables
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For complete information about CPU utilization and how to troubleshoot utilization problems, see the
document
on Cisco.com.
Troubleshooting Power over Ethernet (PoE)
Table 51-4
Troubleshooting CPU Utilization Problems
Type of Problem
Cause
Corrective Action
Interrupt percentage value is almost
as high as total CPU utilization value.
as high as total CPU utilization value.
The CPU is receiving too many packets
from the network.
from the network.
Determine the source of the network
packet. Stop the flow, or change the
switch configuration. See the section on
packet. Stop the flow, or change the
switch configuration. See the section on
Total CPU utilization is greater than
50% with minimal time spent on
interrupts.
50% with minimal time spent on
interrupts.
One or more Cisco IOS process is
consuming too much CPU time. This is
usually triggered by an event that activated
the process.
consuming too much CPU time. This is
usually triggered by an event that activated
the process.
Identify the unusual event, and
troubleshoot the root cause. See the
section on
troubleshoot the root cause. See the
section on
Figure 51-1
Power Over Ethernet Troubleshooting Scenarios
Symptom or problem
Possible cause and solution
No PoE on only one port.
Trouble is on only one switch port. PoE and
non-PoE devices do not work on this port, but
do on other ports.
non-PoE devices do not work on this port, but
do on other ports.
Verify that the powered device works on another PoE port.
Use the show run, show interface status, or show power inline detail
user EXEC commands to verify that the port is not shut down or error
disabled.
user EXEC commands to verify that the port is not shut down or error
disabled.
Note
Most switches turn off port power when the port is shut down,
even though the IEEE specifications make this optional.
even though the IEEE specifications make this optional.
Verify that the Ethernet cable from the powered device to the switch port
is good: Connect a known good non-PoE Ethernet device to the Ethernet
cable, and make sure that the powered device establishes a link and
exchanges traffic with another host.
is good: Connect a known good non-PoE Ethernet device to the Ethernet
cable, and make sure that the powered device establishes a link and
exchanges traffic with another host.
Verify that the total cable length from the switch front panel to the
powered device is not more than 100 meters.
powered device is not more than 100 meters.
Disconnect the Ethernet cable from the switch port. Use a short Ethernet
cable to connect a known good Ethernet device directly to this port on
the switch front panel (not on a patch panel). Verify that it can establish
an Ethernet link and exchange traffic with another host, or ping the port
VLAN SVI. Next, connect a powered device to this port, and verify that
it powers on.
cable to connect a known good Ethernet device directly to this port on
the switch front panel (not on a patch panel). Verify that it can establish
an Ethernet link and exchange traffic with another host, or ping the port
VLAN SVI. Next, connect a powered device to this port, and verify that
it powers on.
If a powered device does not power on when connected with a patch cord to
the switch port, compare the total number of connected powered devices
to the switch power budget (available PoE). Use the show inline power
and show inline power detail commands to verify the amount of
available power.
the switch port, compare the total number of connected powered devices
to the switch power budget (available PoE). Use the show inline power
and show inline power detail commands to verify the amount of
available power.
For more information, see
No PoE On One Port
on Cisco.com.