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Total Errors
Shows the total number of errors that
have occurred per poll, it should be a small
percentage of the readable frames figure.
Runts
Shows the number of frames received with
octet counts less than the minimum legal size
(512
b
its), which were not involved in a collision
on
the segment being monitored
. Runt frames are the
result of collisions
on other segments
and are
propagated around the network; this is a normal part
of Ethernet operation. An excessive number of runts
or collisions is an indication of congestion. You may
need to consider segmenting your network
(separating the busiest parts).
Readable
Shows the number of frames received that
are of valid length and have not suffered a collision
or FCS error. Look for unusual increases in traffic rate;
this can indicate a potential problem.
Broadcast
Shows the number of frames received
which are addressed to all devices. The number of
broadcast frames is normally a small percentage of
the value seen for unicast (single address) frames.
A
h
igh level of broadcast frames can adversely affect
network performance.
Collisions
Shows the number of frames for which a
transmission collision was detected. Collisions are a
normal part of Ethernet operation and occur if two or
more devices attempt to transmit at the same time.
A sudden sustained increase in the number of
collisions can indicate a problem with a device,
particularly if it is not accompanied by a general
increase in traffic. On coaxial segments an increase
in collisions can also indicate faulty cabling.
The values shown in the Activity/Errors graph are
per poll period, not per second. To change the poll
period, see
“Accessing the Hub” on page 4-6
.
16710.bk : MANAGING.FRM Page 20 Tuesday, October 7, 1997 11:38 AM