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Token Ring Statistics
The following Token Ring Statistics are displayed in this window. Information that cannot be
obtained from the hardware or support software is indicated by N/A.
Lost Frame Errors - indicates that a
sending station was unable to complete the transmission because the frame
that was sent never returned to the originator. When a station sends a
frame, that frame normally returns after completing the circuit. If the
frame does not return intact, this error will increment. These errors may occur if another station inserts itself into a ring
or removes itself from the ring, interrupting the clock cycle. Large noise
spikes, such as lightning, could also cause these errors. If you see excessive Lost Frame errors, there may be a problem with
the Multi-Access Unit (MAU) or hub. Use a network analyzer to isolate the
problem area. OID: 1.3.6.1.2.1.10.9.2.1.7 - dot5StatsLostFrameErrors Internal Errors - indicate that the
NIC has detected a problem with
itself. Run the diagnostics from the NIC manufacturer to verify that a
problem exists. You may need to replace the NIC. OID: 1.3.6.1.2.1.10.9.2.1.6 - dot5StatsInternalErrors Receive Congestion - increments when
a station receives a frame, but cannot copy the data for some reason. The
station may not have enough buffer space to copy the data. Excessive traffic to a specific station may cause Receive Congestion
Errors. If certain stations continue to experience Receive Congestion
Errors, check the network design. It is also possible that the software on
the PC is not running efficiently enough to handle interrupts from the
network. OID: 1.3.6.1.2.1.10.9.2.1.8 - dot5StatsReceiveCongestions Token Errors are reported by the
active monitor for one of the following reasons:
The active monitor detects that a frame has
gone around the ring more than once, either because
the sender removed itself from the ring before
stripping the frame, or because there are two active
monitors present on the network. The active monitor
will purge the network and clear the condition in
either case. A station reserved a token at a high priority
and then removed itself from the network. The active
monitor will detect the token traversing the ring
more than once as it searches for the station that
requested the high priority. The active monitor will
purge the ring. The active monitor detects that no token or
frame is received for 10 milliseconds. When several
stations insert or remove themselves from the ring
at the same time the counter will escalate rapidly.
This condition could occur when the power is off
temporarily and then returned. In this example,
several stations would try to insert themselves onto
the ring at the same time, disrupting the signal. If
this condition appears to occur for no known reason,
however, check your Multi-Access Unit (MAU). Use a
network analyzer to isolate the problem area. The active monitor detected a token that was
returned to it containing a token violation. In this
case, you will also see line errors along the ring.
The active monitor will purge the ring, but also
check for the following: Failing
cable - Packet data
traveling through shorted or damaged
cabling may become corrupt before
reaching the destination station and
cause line errors and token errors.
Segment
not grounded properly -
Improper grounding of a segment may
allow ground-induced noise to
corrupt data flow and cause line
errors and token errors. Noisy
cable - Interference or
noise produced by motors or other
devices can distort the signals and
cause CRC/Alignment errors, which
will increment the line error count
and may cause token errors.
If you cannot find the problem after checking the above conditions,
use a network analyzer to isolate the station corrupting the frame.
The analyzer should indicate which station is causing the problem
and let you know if the NIC should be replaced.
OID: 1.3.6.1.2.1.10.9.2.1.10 - dot5StatsTokenErrors
Frame Copy Errors - occurs when a
NIC receives a frame that is destined exclusively for itself, but
the NIC detects that a station upstream has set the address
recognize bit and copied the frame. This means that you have two
NICs with the same network physical address, and you must change one
of the addresses. Each NIC must have a unique network physical
address.
OID: 1.3.6.1.2.1.10.9.2.1.9 - dot5StatsFrameCopiedErrors
Transmit Beacons - increments when
there is a break on the Token Ring or you have a defective NIC on
the ring. If you see even one transmit beacon, investigate the
problem immediately.
The break is detected by the station immediately downstream of the
break when that station stops receiving tokens or frames. This
station then sends a series of beacon frames around the ring to
notify the ring that a break has occurred immediately upstream.
A network analyzer will help to pinpoint the station that is sending
the beacon frames and identify which station is directly upstream of
the station sending the beacon.
OID: 1.3.6.1.2.1.10.9.2.1.14 - dot5StatsTransmitBeacons
Abort Transmit Errors - increments
when a station transmits an abort delimiter while transmitting.
An aborted transmit occurs if the NIC is unable to complete the
transmission of a frame that it has already started onto the
network. For example, if the NIC was unable to access its packet
buffer memory fast enough to keep pace with sending the data stream
onto the wire, the NIC will abort the transmit. When a NIC aborts
the transmit, it places a special bits sequence on the wire known as
an abort delimiter, which signals to other stations on the Token
Ring that the packet data is invalid.
Many NICs do not support aborting transmits, preferring instead to
shut down with a fatal error and remove the NIC from the ring. Those
NICs that support aborting transmits will report this error.
If this error is reported, run the diagnostics from the NIC
manufacturer to see if there is a problem.
OID: 1.3.6.1.2.1.10.9.2.1.5 - dot5StatsAbortTransErrors
Removes - increments when the
manager station issues a "Remove station from the ring" command. See
your network administrator to determine why the station was removed
from the ring.
OID: 1.3.6.1.2.1.10.9.2.1.17 - dot5StatsRemoves
Soft Errors - increments when the
NIC detects recoverable errors. These errors are typically reported
when nodes enter and exit the Token Ring. These are considered
normal, nonfatal errors. The NIC will correct the error, but the
error will be reported to the LAN management station and counted.
Check other error counts to determine if a serious error has
occurred.
OID: 1.3.6.1.2.1.10.9.2.1.1 - dot5StatsSoftErrors
Recoveries - increments any time
the active monitor changes from one station to another. The active
monitor changes when the current active monitor removes itself from
the network or has detected a problem with itself. If this item
increments excessively, check the other error counts to see if a
problem exists.
OID: 1.3.6.1.2.1.10.9.2.1.15 - dot5StatsRecoverys
Hard Errors - usually happen in
conjunction with transmitted beacons. It increments each time a
station receives or sends a beacon, thus occurring numerous times
when a beacon is being transmitted.
If the Transmit Beacons count is incrementing as well, then this
interface is sending beacons on the network. If Transmit Beacons is
not incrementing, then this interface is not transmitting beacons,
but detecting beacons being sent.
A network analyzer will help to pinpoint the station that is sending
the beacon frames and identify which station is directly upstream of
the station sending the beacon.
Perform the following steps:
Check the station immediately upstream from the
station that is sending the beacon. Swap out the
transceiver, transceiver cable, and transceiver
attachment point, one at a time. If you find a
faulty component, replace it. Check the receiver on the station that sent
out the
beacon frames to ensure that it is capable of
receiving frames. If the receiver is not working
properly, the NIC may have erroneously assumed that
there were no frames or tokens. Run diagnostics from
the NIC manufacturer to help you pinpoint the
problem. Check the cabling for breaks or disruptions.
Your Multi-Access Unit (MAU) or hub may be at
fault.
Use the diagnostics from the MAU manufacturer to
determine if a problem exists.
OID: 1.3.6.1.2.1.10.9.2.1.12 - dot5StatsHardErrors
Lobe Faults - are caused when the
network is in test mode and finds a problem with one of the lobe
wires running from the Multi-Access Unit (MAU) to each station. The
network enters test mode under two conditions:
When a station powers on and attempts to insert
itself onto the network, the test on the lobe wire
will begin. If the test fails, a lobe wire fault
occurs. If hard errors occur, the NIC will enter test
mode. If the self-test fails, a lobe wire fault will
occur.
If a Lobe Wire Fault occurs, check for the following:
Failing cable
- Make sure that your lobe wire
is working and intact. Failing repeater,
transceiver, or controller card -
Repeaters, transceivers, and controller cards can
disrupt the network signal, transmit erroneous
signals on the wire, or ignore incoming packets.
Perform the following steps:
If your NIC is
continuously transmitting,
it will cause erroneous
signals or "jabber." Replace
a jabbering receiver to
ensure proper network
performance. Swap out the
transceiver, transceiver
cable, and transceiver
attachment point, one at a
time. If you find a faulty
component, replace it. Your Multi-Access Unit
(MAU) or hub may be at
fault. Use the diagnostics
from the MAU manufacturer to
determine if a problem
exists.
OID: 1.3.6.1.2.1.10.9.2.1.16 - dot5StatsLobeWires
Line Errors - increments each time
a station detects a line error. Each station either repeats or
copies a frame and checks the frame for validation. If the data in
the frame is corrupted, each station that detects the corrupted
frame increments its own line error count.
OID: 1.3.6.1.2.1.10.9.2.1.2 - dot5StatsLineErrors
Signal Loss - usually happens in
conjunction with other errors, such as burst errors, token errors,
line errors, and transmitted beacons. This error indicates that the
station temporarily or permanently lost the clock signal on the
Token Ring. Check other error conditions to determine if a serious
error has occurred.
OID: 1.3.6.1.2.1.10.9.2.1.13 - dot5StatsSignalLoss
Burst Errors - increments every
time the adapter detects the absence of clock transitions. Burst
errors occur in Token Ring networks when the signal is momentarily
disrupted. Each time a station inserts itself into the ring or
removes itself from the ring, a burst error may occur.
If you detect that one station has an abnormally high burst error
count compared to other stations, you may need to replace the NIC.
For example, if most stations average 2 burst errors per day, and
one station shows 27, that station may have a faulty NIC. The
station that is directly downstream of the device causing the
problem usually detects the burst error. Use the Upstream Address of
the station detecting Burst Errors to determine the faulty NIC.
If excessive burst errors continue to occur on the ring, you may
need to replace the Multi-Access Unit (MAU) or hub. Use a network
analyzer to isolate the problem area.
OID: 1.3.6.1.2.1.10.9.2.1.3 - dot5StatsBurstErrors
Frequency Errors - occur when a
station detects that the active monitor is not working in the proper
frequency. Ring Recovery will occur and another active monitor will
be chosen.
The active monitor generates a clock signal, which it passes to each
standby monitor. The standby monitor compares this signal to its own
reference clock. If the signal is not within the proper frequency
boundaries, a frequency error occurs.
If you see frequency errors, use a network analyzer to determine
which station was the active monitor causing the problem. Remember
when you use your analyzer that the station with the problem is not
the current active monitor the active monitor experiencing the
problem was replaced when the problem was detected.
OID: 1.3.6.1.2.1.10.9.2.1.19 - dot5StatsFreqErrors
AC Errors - are also referred to as
Address Recognized Indication/Frame Copied Indicator (ARI/FCI)
errors. This error occurs when a station detects that an upstream
station did not correctly set the bits on a frame.
If an AC error occurs, perform the following steps during your next
planned maintenance:
Ensure that the NIC is compliant with the
protocol
in use. The NIC that did not set the bit (the
station directly upstream of the station that
reported the problem) is not participating in the
low level protocol and may not be completely
compliant with 802.5 protocol. Replace the NIC to see if the problem still
occurs.
OID: 1.3.6.1.2.1.10.9.2.1.4 - dot5StatsACErrors
Single Station - increments when
the interface senses that it is the only station on the ring. This
will happen if the interface is the first one up on a ring, or if
there is a hardware problem. Check for the following:
Your Multi-Access Unit (MAU) or hub may be at
fault. Use the diagnostics from the MAU manufacturer
to determine if a problem exists. Check the cable between the NIC and the MAU.
Replace the cable if necessary. Run the diagnostics from the NIC manufacturer
to determine if there is a problem with the NIC.
Replace the NIC if necessary.
OID: 1.3.6.1.2.1.10.9.2.1.18 - dot5StatsSingles
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