The FN100 Chassis View
a MAC layer packet formation problem, or from a cabling problem that is corrupting or losing data.
FCS
The number of frames received on a particular interface that are an integral number of bytes in length, but do not pass the FCS (Frame Check Sequence) check. FCS, or Frame Check Sequence, errors occur when packets are somehow damaged on transit. When each packet is transmitted, the transmitting interface computes a frame check sequence (FCS) value based on the contents of the packet, and appends that value to the packet. The receiving interface performs the same computation; if the FCS values differ, the packet is assumed to have been corrupted and is counted as an FCS error.
SQE Test
Displays the number of times that the SQE Test Error message is generated by the PLS sublayer on the selected interface. The SQE (Signal Quality Error) Test tests the collision detect circuitry after each transmission. If the SQE Test fails, a SQE Test Error is sent to the interface to indicate that the collision detect circuitry is malfunctioning.
Carrier Sense
Displays the number of times that the carrier sense condition was lost or never asserted when attempting to transmit a frame on a particular interface. Carrier sense describes the action an interface desiring to transmit will take to listen to the communication channel to see if any other interface is transmitting. If a “carrier is sensed,” the sensing interface will wait a random length of time, and then attempt to transmit.
Frame Too Long
Displays the amount of frames received on this interface that exceed the maximum permitted frame size.
Internal MAC
The number of frames that failed to be received by the interface due to an internal MAC sublayer receive error. These errors are only counted if a Frame Too Long, Alignment, or FCS Error did not occur along with the internal MAC error.
Receive Errors
Displays the total number of receive errors of all types that were detected by the selected interface while it was receiving a transmission.
Transmission Errors
Deferred
Displays the number of frames for which the first transmission attempt on this interface is delayed because the medium is busy.
Managing the Hub |