Information Technology Reference
In-Depth Information
Table5-2
show interfaces fddi Field Descriptions (continued)
Field
Description
5 minute input rate,
5 minute output rate
Average number of bits and packets transmitted per
second in the past five minutes.
The five-minute input and output rates should be used
only as an approximation of traffic per second during a
given five-minute period. These rates are exponentially
weighted averages with a time constant of five minutes. A
period of four time constants must pass before the average
will be within 2 percent of the instantaneous rate of a
uniform stream of traffic over that period.
packets input
Total number of error-free packets received by the system.
bytes
Total number of bytes, including data and MAC
encapsulation, in the error-free packets received by the
system.
no buffer
Number of received packets discarded because there was
no buffer space in the main system. Compare with ignored
count. Broadcast storms on Ethernet networks and bursts
of noise on serial lines are often responsible for no input
buffer events.
broadcasts
Total number of broadcast or multicast packets received
by the interface.
runts
Number of packets that are discarded because they are
smaller than the medium's minimum packet size.
giants
Number of packets that are discarded because they exceed
the medium's maximum packet size.
CRC
Cyclic redundancy checksum generated by the
originating LAN station or far-end device does not match
the checksum calculated from the data received. On a
LAN, this usually indicates 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
a station transmitting bad data.
frame
Number of packets received incorrectly that have a CRC
error and a noninteger number of octets. On a LAN, this
is usually the result of collisions or a malfunctioning
Ethernet device. On an FDDI LAN, this also can be the
result of a failing fiber (cracks) or a hardware
malfunction.
overrun
Number of times the serial receiver hardware was unable
to hand received data to a hardware buffer because the
input rate exceeded the receiver's ability to handle the
data.
