HP 3000 Manuals HP 3000 Manuals
NS3000/iX LAN Link Statistics
The following section describes the data that is output when you issue
the LINKCONTROL command to obtain statistics relating to NS3000/iX LAN
Links.
LINKSTATE Parameter Fields
Figure A-5 provides an example of the data that is displayed when you
issue the LINKCONTROL linkname;STATUS=LINKSTATE command:
Linkname: SYSLINK Linktype: IEEE802.3 Linkstate: CONNECTED
Figure A-5. LINKSTATE Command for LAN Link
Linkname. The Linkname field specifies the name of the link.
Linktype. The Linktype field specifies the type of link, such as LAP-B
or IEEE 802.3, that is being monitored.
Linkstate. The Linkstate field specifies the current state of the link.
The possible link states are as follows:
* Connected
* Not connected
NOTE Some of the parameter descriptions that follow vary according to
whether your LANIC is a CIO card or an NIO card.
CONFIGURATION Parameter Fields
The CONFIGURATION parameter for IEEE 802.3 links displays several fields
in addition to the LINKSTATE parameter field. Figure A-6 provides an
example of the data that is displayed when you issue the LINKCONTROL
linkname;STATUS=CONFIGURATION command:
Physical Path: 4.6
Inbound Buffer Size: 1536 (CIO only)
Inbound Number of Buffers: 64 (CIO only)
Inbound Buffers Available: 41 (CIO only)
Current Station Address: 08-00-09-02-3D-9B
Default Station Address: 08-00-09-02-3D-9B
Current Receive Filter: bad(0) multi(1) broad(1) any(0)
Current Multicast Addresses: 09-00-09-00-00-01
Figure A-6. LAN CONFIGURATION Parameter Output (Sample for CIO Output)
Physical Path. The Physical Path field displays the current physical
path for the LANIC card as specified in the NMMGR configuration file.
Inbound Buffer Size. The Inbound Buffer Size field displays the current
size of the receive buffer that are configured for this system through
NMMGR. This field will not print for NIO cards, since there may be
multiple inbound buffer sizes.
Inbound Number of Buffers. The Inbound Number of Buffers field displays
the number of receive buffers that are configured for this system through
NMMGR. This field will not print for NIO cards.
Inbound Buffers Available. The Inbound Buffers Available field displays
the number of unused or unassigned Inbound Buffers that are available to
this system. This field will not print for NIO cards.
Current Station Address. The Current Station Address field is a display
of the six (6) byte address to which the node is configured to respond.
This address is used whenever frames are sent to the network media. The
default station address is used unless it is overridden in the NMMGR link
configuration screen. If this field is changed, then the station address
of this node is changed. Make sure that you note this new address in the
system manager log.
Default Station Address. The Default Station Address field is the
default value for the Current Station Address described above. The
default station address is determined by the specific LANIC card. It is
also printed on the LANIC card. If the card is changed for any reason,
the Default Station Address of this node will change.
Current Receive Filter. The Current Receive Filter field has a current
value. The current value is currently used by the LANIC card.
Receive Filter bad (). The Receive Filter bad () field is either enabled
(1) or disabled (0). When enabled, any bad frames that are received by
the LANIC are passed to the driver. When disabled, bad frames are
discarded. Any bad frames are counted in the statistics.
Receive Filter multi (). The Receive Filter multi () field is either
enabled (1) or disabled (0). When enabled, you can specify a list of
specified multicast frames to be received by the LAN hardware card. The
list can contain up to 64 multicast addresses to be downloaded to the
LANIC and is displayed when this field is entered.
Receive Filter broad (). The Receive Filter broad() field is either
enabled (1) or disabled (0). When enabled, the LAN hardware card
receives frames sent to the broadcast address.
Receive Filter any(). The Receive Filter any() field is either enabled
(1) or disabled (0). When enabled, the LANIC attempts to receive all
frames from the network media. When disabled, only those frames sent to
the LANIC are received.
Receive Filter k_pckts() (NIO card only). The Receive Filter k_pckts()
filed is either enabled (1) or disabled (0). When enabled, the LANIC
keeps frames received from the network media, even if no buffers are
currently posted to the card. If this option is not enabled, the frames
will be dropped.
Receive Filter x_pckts() (NIO card only). The Receive Filter x_pckts()
field is either enabled (1) or disabled (0). When enabled, any XID or
TEST commands sent to DSAP 0 will be responded to by the driver, and not
the card.
Current Multicast Addresses. The Current Multicast Addresses field
contains a list of all multicast addresses to which the LANIC responds.
The default multicast address list contains no addresses. If no
multicast addresses are specified, the following message is printed:
Current multicast address list is empty
Multicast addresses are configured through NMMGR. The maximum number of
multicast addresses allowed is 16. The meanings of the following
specific multicast addresses are as follows:
09-00-09-00-00-01 Probe address
09-00-09-00-00-02 2nd probe address
09-00-09-00-00-03 LAN analysis (LANDAD)
09-00-09-00-00-04 DTC boot address
STATISTICS Parameter Fields
The STATISTICS parameter for IEEE 802.3 links displays many fields in
addition to the LINKSTATE parameter fields. The CONFIGURATION parameter
fields are not displayed when this parameter is used. Figure A-7
provides an example of the data that is displayed when you issue the
LINKCONTROL linkname;STATUS=STATISTICS command:
Transmits no error 1 Receives no error 343
Transmits error 0 Receives error 0
Out of TX bufs 0 Out of Rx bufs 0
Transmits deferred 0 Carrier losses 0
Transmits 1 retry 0 Reflectometer 0
Transmits >1 retry 0 CRC errors 0
Transmits 16 collisions 0 Whole byte errors 0
Transmits late collision 0 Size range errors 0
802 chip restarts 0 Frame losses 0
Heartbeat losses 0
Figure A-7. LAN STATISTICS Parameter Fields (Sample for CIO Output)
This command displays statistics about data transmitted across the link.
All field values, except for those under Receive Filter, are summations.
Over time, the values in these fields reach their maximum possible value.
When this occurs, these fields can only be reset manually.
Transmits no error. The Transmits no error field specifies the number of
frames that were successfully transmitted onto the medium. This includes
the number of frames that were successfully transmitted on the first
attempt, as well as frames that were successfully transmitted after being
deferred or that experienced one or more collisions. The maximum value
of this 32-bit field is 4294967295.
Receives no error. This field specifies the number of frames that were
successfully received over the medium. This includes the number of
frames that were successfully received on the first attempt, as well as
frames that were successfully received after being deferred or that
experienced one or more collisions. The maximum value of this 32-bit
field is 4294967295.
Transmits error. The Transmits error field specifies the number of
transmission errors sent across the link. The value in this field
specifies the number of frames which, due to errors on the link, were
never transmitted. Although this value is commonly greater than 5% of
the total number of frames transmitted, if it reaches or exceeds 5% of
the total number of frames, check the hardware or check to see if the LAN
is overloaded.
Receives error. The Receives error field specifies the number of
transmission errors that were received from the link. The value in this
field specifies the number of frames which were received, but were
corrupted due to errors on the link. This value includes all frames
which were discarded because of the setting of the current receive
filter.
Out of Tx bufs (CIO card only). The Out of Tx bufs field specifies the
number of times that the LAN device adaptor (DA) reported to the driver
that no transmit buffers were available. The maximum value of this
32-bit field is 4294967295.
Out of Rx bufs (CIO card only). The Out of Rx bufs field indicates the
number of times the LANIC card reported to the driver that no receive
buffers were available. This indicates only that the next buffer space
was full and that the buffer pointer could not be incremented to an
available buffer (the buffer pointer is incremented only after the driver
requests the next frame). This also does not indicate that any frames
were lost, however if another frame arrives before a receive buffer is
made available, that frame will be lost. The value of this field should
be very low. Retransmissions will occur if the link is out of Rx bufs.
The maximum value for this 32-bit field is 4294967295.
Transmits deferred. The Transmits deferred field indicates the number of
frames that deferred to other traffic before being transmitted onto the
network. This means that the LAN card had to wait for carrier to drop,
and stay dropped for 9.6 nanoseconds, before attempting to transmit the
frame. This statistic only counts the number of frames that were
deferred and later transmitted without collision.
Carrier losses. The Carrier losses field indicates that the transmitting
node turned off the carrier signal on the cable. This occurred for one
of the following reasons:
* The stub cable is not connected to the frontplane connector.
* The AUI (or AUI pigtail for ThinMAU) is not connected to the stub
cable.
* The MAU is broken.
* If using thick LAN cable, there may be a short close to the MAU
(ThinLAN cable shorts show up as a retry error as described in the
Transmits 16 collision field description).
If the LAN continuously loses carrier, the problem is probably caused by
a disconnected AUI or stub cable. Make sure that all connectors from the
frontplane of the LAN hardware card to the MAU are connected securely.
NOTE Collisions occur on IEEE 802.3 Local Area Network (LAN) links
whenever two nodes on the link attempt to transmit data at the same
time. When a collision occurs, the nodes which were involved in
the collision each wait a random amount of time, called random
backoff, before attempting to again transmit the packet along the
link. If collisions continuously occur, check the terminators.
Many of the fields described in this section are incremented
whenever a collision occurs.
Transmits 1 retry. This field indicates the number of frames that
collided once before being transmitted successfully. This means that the
random backoff strategy was only used once.
Reflectometer (CIO card only). The reflectometer field is similar in
function to a TDR (Time Domain Reflectometer). The statistic holds the
time count between the pulse and a reflection. Whenever a retry error
occurs, the time in bit times (100ns) from when the frame started to
transmit until the collision occurred is stored by this statistic. This
can be useful for grossly determining the location of an opening in a
cable, or possibly, a short in a ThinLAN cable. This field is erased
after every transmit and is not updated after an external loopback frame
is transmitted onto the link.
While this statistic may aid in pinpointing a problem without the need to
do an actual TDR test, it should be noted that this statistic calculates
the distance using a rough estimate (bit time) and can be inaccurate.
This statistic should never be used as the only means of locating a cable
fault. However, if this field is not equal to 0, then the hardware of
the node is a likely cause of the failure.
The reflectometer field, for a thick LAN cable, is calculated in the
following manner:
The ThickLAN velocity of propagation = .77c
Where c (the speed of light) = 3x10 E8
The bandwidth of a LAN = 10Mb/sec.
Before determining the level of cable fault isolation, you must first
determine how many meters of the cable are covered per bit time. You
then divide .77c by 10Mb/sec. This translates into:
7x10E-2) x (3x10E8)
__________________ = 231 meters
10E6 b/sec)
Therefore, in order to pinpoint a fault in a thick LAN cable by the value
of this field, multiply the field value by 231 meters.
The accuracy of the reflectometer field is plus or minus 1/2 bit time, or
115m. Using this calculation, the location of the cable fault is
determined by the following formula:
(value of field x 231 meters) +\- 115m
Since the maximum length of a cable is 500m, the value of this field
would be 0, 1 or 2, and would pinpoint a cable fault to 1 of 3 sections
of cable.
If this value were to be used for isolating a cable fault in a ThinLAN
cable, the value 0.65 would be substituted for .77c in the calculation
above. (The ThinLAN velocity of propagation is .65c).
Transmits >1 retry. The Transmits >1 retry field indicates the number of
frames that collided more than one, but fewer than 16 times, before being
transmitted successfully onto the link. If the frame was not transmitted
successfully (more than 16 attempts were made without success), then the
card aborts transmission of this frame, and it counts the event as a
retry error (see the Transmits 16 collision field).
CRC errors. The CRC errors field specifies the number of cyclic
redundancy check (CRC) errors that were seen on the link. A CRC error
indicates that the frame was checked using CRC-32 frame-checking, but
that the value obtained by the CRC did not match the CRC value contained
within the packet.
Normally there will be an equal number of alignment errors. If alignment
errors occur frequently, one of the following may be the cause:
* A LANIC is not listening to the link before transmitting.
* A repeater that is performing poorly.
* A section of LAN coax which contains an impedance.
* The driver level of a MAU is set too low.
Transmits 16 collisions. The Transmits 16 collisions field indicates the
number of times a frame or frames were not transmitted because 16
consecutive collisions occurred. This commonly occurs in the protocol
during periods of high network utilization. If your node is experiencing
continuous retry errors, the problem is most likely that a terminator has
been removed from the cable. Other possible causes include the
following:
* There is an opening in the cable.
* If ThinLAN cable is used, the AUI may be disconnected.
* The LAN cable may shorted.
Whole byte errors. The Whole byte errors field is the number of frames
received that were not an integer multiple number of bytes long. This
occurs when an entire byte is not transmitted. This usually also causes
the CRC error to be set.
Transmits late collision. This field indicates that a frame was active
in the network for a longer time than is permitted by the protocol. The
IEEE 802.3 protocol expects each frame to be transmitted within one slot
time (the expected time for a 512 bit packet to traverse the entire
network). The slot time exceeds the amount of time a single frame should
need to traverse the entire network.
A value in this field indicates that a network problem caused a late
collision. A late collision is one in which the collision occurs after
one slot time has passed and another node, sensing that the network is
inactive, begins to transmit a frame. Late collisions are caused by one
of the following:
* Broken LAN cards in the network.
* A network that is too long.
A network can be made too long by installing too many repeaters between
nodes. HP MAUs inform the LANIC card of collisions after the 512 bit
timer expires even though IEEE 802.3 standards do not require the MAU to
monitor the link beyond that time. No attempt is made to retransmit a
frame after a late collision.
Size range errors. The Size range errors field indicates the number of
frames received that are not within the allowable size range. The
allowable size range is 64-1518 bytes long. Unless the save bad frames
bit is set on the LAN hardware card, the LAN hardware card throws these
packets out.
802 chip restarts. The 802 chip restarts field was initially used to
count the number of times that a specific version of the LAN chip locked
up. This problem was remedied by a new version of that chip, however,
this field still returns a value when one of the following events occurs:
* An AUI cable that is shorted and sending an intermittent signal to
any of the connectors.
* Infinite deferral errors.
* "Jabbering" MAU.
* Noise from another node.
* Bad chips.
The value of the 802 chip restarts field provides information about the
performance of the LANIC card and the status of the LANCE chip status for
overflow/underflow errors (this is monitored by firmware).
Frame losses. The frame losses field indicates the number of times that
the LAN controller chip indicated that it has lost a frame. After some
delta period of time following a transmission, no collision detect is
seen. This is typically because there are no free receive buffers when a
frame arrives.
Receives Dropped (NIO card only). The Receives Dropped field indicates
the total number of frames that were dropped because there was no receive
buffer posted.
Receives Broadcast (NIO card only). The Receives Broadcast field
indicates the total number of frames received that were addressed to a
broadcast address. If no broadcasts have been received, check the
current receive filter to ensure that broadcasts are enabled. If
broadcasts are enabled and no broadcasts have been received, this may be
an indication of a faulty LANIC card.
Receives Multicast (NIO card only). The Receives Multicast field
indicates the total number of frames received that were addressed to a
multicast address. If no multicast frames are being received, check to
make sure that the desired multicast address(es) are listed as part of
the current multicast addresses.
Heartbeat losses. The Heartbeat losses field indicates that no SQE
heartbeat was seen after a transmission and when IEEE 802.3 stub cable
was connected. After a successful transmission, the 802.3 MAU sends an
SQE message, called a "heartbeat," through the Control In wire of the
AUI. This heartbeat function lets the card know that the MAU is still
functioning properly.
NOTE This statistic is not to be set if the Ethernet stub cable is
connected.