Packet Error Gauge - Cisco Catalyst Express 500-24LC User Manual

Chapter 4 Monitoring

Packet Error Gauge

Table 4-5 Types of Packet Errors
Runt packets
Giant packets
Cyclic redundancy
checksum (CRC) errors
Overrun packets
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The Packet Error gauge shows the total packet error percentage for the switch.
Each bar in the gauge represents 10 percent and does not show increments that are
less than 10 percent. The gauge does not show total packet errors under 5 percent.
Data is collected at each 60-second system refresh. To see a graph that shows
packet error percentages over incremental instances in time (by 60 seconds, 60
minutes, 24 hours, or 14 days), see the
The packet error percentage is calculated by comparing two values:
The total number of packets that are sent and received
•
The total number of packets with errors that are sent and received
•
If the packet-error percentage is high (that is, above 10 percent), the switch
bandwidth utilization might also be too high (a sign that the network is
congested). Other causes for packet errors are faulty cabling and port
misconfigurations, such as a duplex mode mismatch. These problems can cause
network users to experience intermittent connectivity or loss of connectivity to
network resources (such as servers and printers) or to the Internet. Excessive
collisions can cause transmission delays. For example, users might experience
excessive delays in sending or receiving information through the network.
The Port Statistics window displays some of the types of packet errors
collected by the switch. The type of packet error can help you to identify a more
precise cause for some network problems. For more information about port
statistics, see the "Check the Port Statistics" section on page
These are some types of packet errors.
Packets that are smaller than the allowed minimum size (less than 64 bytes).
Packets that are larger than the allowed maximum size (more than 1518
bytes).
Errors generated by the originating LAN station or far-end device do not
match the checksum calculated from the data received. On a LAN, this
usually means noise or transmission problems on the LAN interface or the
LAN bus itself. A high number of CRCs is usually the result of collisions
or of a station sending bad data.
Packets that the receiving device was unable to receive.
"Packet Error Graph" section on page
User Guide for the Catalyst Express 500 Switches
Check the Dashboard
4-16.
(Table 4-5)
4-18.
4-11