Alerts

Interpreting the Alert Log - Automatic Fault Finding

Table 5-1. Common Faults

Fault

Description, Cause and Actions

 

 

Too many

Description: A device on this port is transmitting packets shorter than 64 bytes or longer than 1518 bytes

undersized/giant

(longer than 1522 bytes if tagged), with valid CRCs.

packets

 

 

 

Possible Causes: a misconfigured NIC or a malfunctioning NIC, NIC driver, or transceiver

 

Actions:

 

1.

Check the NIC for a misconfiguration.

 

2.

Update the NIC driver software.

 

3.

Replace the malfunctioning NIC or transceiver.

 

4.

Check for a short-circuit in the cable patch connected to this port.

 

 

Excessive

Description: A device on this port is continually transmitting packets (jabbering). This is detected as

jabbering

oversize packets with CRC errors.

 

Possible causes: A misconfigured NIC, or a malfunctioning NIC or transceiver. It could also be caused by

 

a short-circuit in the network cable path.

 

Actions:

 

1.

Check NIC for a misconfiguration.

 

2.

Update the NIC driver software.

 

3.

Replace the NIC or transceiver.

 

4.

Check for a short-circuit in the cable path connected to this port.

 

 

Excessive CRC/

Description: A high percentage of data errors was detected on this port.

alignment errors

 

 

 

Possible Causes:

 

Faulty cabling or topology

 

Half/full duplex mismatch

 

Misconfigured NIC

 

Malfunctioning NIC, NIC driver or transceiver

 

Actions:

 

1.

If the port is 100Base-T, make sure the cable, connectors, punch-down blocks, and patch panels

 

 

connecting to the port are Category 5 or better. Verify the installation with a Category 5 test device.

 

2.

Check the directly-connected device for mismatches in half/full duplex operation (half duplex on the

 

 

switch and full duplex on the connected device, or the reverse).

 

3.

Update the NIC driver software.

 

4.

Verify that the network topology conforms to IEEE 802.3 standards.

 

5.

Replace or relocate the cable.

 

6.

Check the wiring closet components, transceivers, and NICs for proper operation.

 

 

 

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