The following section describes the data that is output when you issue the
LINKCONTROL command to obtain statistics relating to NS 3000/iX
100VG-AnyLAN Links.
LINKSTATE Parameter Fields
The following is an example of the data that is displayed when you issue the
LINKCONTROL linkname;STATUS=LINKSTATE command:
Linkname — The Likname field specifies the name of the link.
Linktype — The Linktype field
specifies the type of link, such as LAP-B, 100VG-802.3, 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
CONFIGURATION Parameter Fields
The CONFIGURATION parameter for 100VG-AnyLAN links displays
several fields in addition to the LINKSTATE parameter field. This is
an example of the data that is displayed when you issue the
LINKCONTROL linkname;STATUS=CONFIGURATION command:
Physical Path: 10/4/8
Current Station Address: 08-00-09-DD-CC-99
Default Station Address: 08-00-09-DD-CC-99
Current Multicast Addresses:
99-00-09-00-00-01 09-00-09-00-00-03 09-00-09-00-00-04
09-00-09-00-00-06
Physical Path — The Physical
Path field displays the current physical path for the adapter card
as specified in the NMCONFIG configuration file.
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 previously. The default station address
is determined by the specific adapter card. It is also printed on
a small label attached to a circuit board on the adapter card. If
the adapter card is changed for any reason, the Default Station Address
of this node will change.
Current Multicast Address List — The
Current Multicast Addresses field contains a list of all multicast
addresses to which the adapter card responds. The default multicast
address list contains no addresses. If no multicast addresses are
enabled, the follow message is printed:
Current multicast address list is empty
Multicast addresses are configured automatically by the network transport(s)
using the adapter card. The maximum number of multicast addresses
allowed is 16. An example of multicast addresses are:
09-00-09-00-00-01
Probe address
09-00-09-00-00-02
Second probe address
09-00-09-00-00-04
DTC boot address
STATISTICS Parameter Fields
The STATISTICS parameter for 100VG-AnyLAN links displays many
fields in addition to the LINKSTATE parameter fields. The
CONFIGURATION parameter fields are not displayed when this
parameter is used. For an example of the data that is displayed when you issue
the LINKCONTROL linkname;STATUS=STATISTICS command:
Transmit bytes norm 1456044817 Receive bytes norm 5308537515
Transmit byets hipri 62029 Receive bytes hipri 0
Transmits norm 2707747 Receives norm 5302073790
Transmits hipri 712 Receives hipri 0
Transmits no error 2708459 Recv broadcast norm 47068412
Transmits dropped 0 Recv broadcast hipri 0
Trans underruns 0 Recv multicast norm 1300291
Recv overruns 0 Recv multicast hipri 0
Recv deferred 123 Receives no error 664709473
CRC or Maxsize error 0 Recv dropped: addr 16002992
Code or Align error 0 Recv dropped: buffer 262
Link disconnects 0 Recv driooedL dna 0
Link speed 100 Recv dropped: other 24785
Link mode 100VG Secs since clear 6173798
Link training result CONNECTED
NOTE: Some of the parameter descriptions vary according to
whether the adapter card is operating at 100Mbps or 10Mbps speed.
For a 100VG adapter card operating in 10Base-T mode, refer to 100Base-T
statistics.
This command displays statistics about data transmitted and
received across the link. Many field values are summations. Over
time, the values in these fields reach their maximum possible value.
When this occurs, these fields can only be reset manually.
Transmit bytes norm — Total
number of bytes successfully transmitted onto the medium at normal
priority. This includes unicast, broadcast, and multicast frames.
It also includes frames for which normal priority was requested,
but which were later automatically boosted to demand priority by
the 100VG-AnyLAN network. The maximum printable value of this 64-bit
field is 17 digits, or about 99 million Gbytes. In the example above,
1.45 billion bytes were transmitted, or about 1.38 Gbytes.
Transmit bytes hipri — Total
number of bytes successfully transmitted onto the medium at high
(demand) priority. This includes unicast, broadcast, and multicast
frames. It does not include frames for which normal priority was
originally requested, but which were later automatically priority-boosted
by the 100VG-AnyLAN network. The maximum printable value of this
64-bit field is 17 digits, or about 99 million Gbytes. In the example
above, 62,029 high priority bytes have been transmitted, or about
60K bytes.
Transmits norm — Total number
of frames successfully transmitted onto the medium at normal priority.
This includes unicast, broadcast, and multicast frames. It also
includes frames for which normal priority was requested, but which
were later automatically boosted to demand priority by the 100VG-AnyLAN
network. The byte count given by Transmit bytes norm is distributed
over this number of frames. The maximum printable value of this
64-bit field is 17 digits, or about 99 million billion frames. In
the previous example, 2.71million frames were transmitted at normal
priority.
Transmits hipri — Total number
of frames successfully transmitted onto the medium at high (demand)
priority. This includes unicast, broadcast, and multicast frames.
It does not include frames for which normal priority was originally
requested, but which were later automatically priority-boosted by
the 100VG network. The byte count given by Transmit bytes hipri
is distributed over this number of frames. The maximum printable
value of this 64-bit field is 17 digits, or about 99 million billion
frames. In the example above, 712 frames were transmitted at high
priority.
Transmits no error — Total
number of frames the adapter card reports it successfully transmitted
onto the medium. These adapter card statistics are periodically
read, and are accumulated by the link driver. The total includes
all unicast, broadcast, and multicast frames, at both normal and
high (demand) priority. It should equal the sum of (Transmits norm
+ Transmits hipri). The maximum printable value of this 64-bit field
is 17 digits, or about 99 million billion frames. In the previous
example, 2.71 million frames were transmitted regardless of priority level.
Transmits dropped — Total
number of frames the link driver discarded because the transmit
queue was full, or because the data to be sent was fragmented beyond
recognition. The maximum value of this 32-bit field is 2147483647.
It would be unusual for this statistic to contain a nonzero value.
Trans underruns — Total number
of frames aborted by the adapter card during transmission because
the remaining data was not made available to the transmit hardware
fast enough. It indicates unexpected latency on the dedicated internal
bus onboard the adapter card. If this condition occurs, the adapter
will automatically adjust to improve the latency, and retransmit
the aborted frame automatically. The maximum value of this 32-bit
field is 2147483647. For this statistic, a value of less than 3
would be considered normal.
Recv overruns — Total number
of address-matched frames that could not be received into the adapter
card, either because prior data was not being removed by the receive
hardware fast enough, or because their size exceeded the maximum
frame size. May indicate unexpected latency on the dedicated internal
bus onboard the adapter card, which cannot be automatically adjusted
by the link driver. The maximum value of this 32-bit field is 2147483647.
It would be unusual for this statistic to contain a nonzero value.
Recv deferred — Number of
times an address-matched receive frame was temporarily held (queued)
by the link driver, because of a momentary lack of DMA resources.
Once those resources became available, the frame was automatically
transferred to the host. The maximum printable value of this 64-bit
field is 17 digits, or about 99 million billion frames. In the previous
example, 123 frames were temporarily held.
CRC or Maxsize error — Number
of cyclic redundancy check (CRC) errors or oversized frames that
were seen during reception by 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
at the end of the frame. CRC errors do not include frames having
alignment or coding errors. Oversized frames are those longer than
1518 bytes. These adapter card statistics are periodically read,
and are accumulated by the link driver. The maximum value of this
32-bit field is 2147483647. A nonzero value in this statistic could
indicate a defective cable, adapter, or hub, a loose connection,
presence of severe electrical noise along the cable path, or a misbehaving
application, adapter, or hub at the transmission end.
Code or Align error — Number
of frames received with an alignment error (not an even multiple
of 4 bits of data) or code errors (an error signal was received
from the 100VG-AnyLAN receive hardware). These adapter card statistics
are periodically read, and are accumulated by the link driver. The
maximum value of this 32-bit field is 2147483647. If alignment errors
occur frequently, one of the following may be the cause:
A 100VG-AnyLAN adapter card is not operating to within 802.12
specifications.
A 100VG-AnyLAN hub is performing poorly.
The 100VG-AnyLAN cable is not CAT-3 or CAT-5 grade.
A section of 100VG-AnyLAN cable contains wire pairs which are not
properly twisted, paired, or of equal length.
Link disconnects — Number
of times the link driver noticed the link had previously been established,
but was no longer up. This may occur because the cable was unplugged,
the hub was powered off, the hub automatically requested a reconnect,
or normally (at link shutdown time). This total does not include
repetitive, failed attempts by the link driver to reestablish the
link. The maximum value of this 32-bit field is 2147483647.
Link speed — Maximum link
speed (either 100 or 10) in millions of bits per second, the link
is currently configured to operate at. When displaying a 100VG-AnyLAN
link operating in 100VG-AnyLAN mode, this value will always be 100.
When a 100VG-AnyLAN link is operating in 10Base-T mode, this value
will always be 10.
Link mode — Electrical mode
the link is currently operating at. When displaying a 100VG-AnyLAN
link operating in 100VG-AnyLAN mode, this value will always be "100VG-AnyLAN".
When a 100VG-AnyLAN link is operating in 10Base-T mode, this value
will be "10Base-T".
Link training result — The
result of the last automatic 100VG-AnyLAN "link training" operation
performed during link establishment. If the cable is connected to
an operational 100VG-AnyLAN hub port, the link is configured for
100VG-AnyLAN operation in NMCONFIG, and the link driver has been
started, this value should be "CONNECTED". Most
other values indicate a problem with the hub port, the connection
to that 100VG-AnyLAN hub port, or the cable grade is not CAT-3 or CAT-5.
Receive bytes norm — Total
number of bytes successfully received over the medium at normal
priority. This includes unicast, multicast, broadcast, and link
training frames. It does not include frames received by the adapter
card but dropped because no upper layer protocol had requested those
frames, or because the link was disconnected. The maximum value
of this 64-bit field is 17 digits, or about 99 million Gbytes. In
the example above, 5.30 billion bytes were received, or about 5.06 Gbytes.
Receive bytes hipri — Total
number of bytes successfully received over the medium at high (demand)
priority. This includes unicast, multicast, and broadcast frames.
It also includes frames for which normal priority was originally
requested by the sender, but which were later automatically priority-boosted
by the 100VG-AnyLAN network. It does not include frames received
by the adapter card but dropped because no upper layer protocol
had requested those frames, or because the link was disconnected.
The maximum printable value of this 64-bit field is 17 digits, or
about 99 million Gbytes. In the example above, no high priority
data has been received.
Receives norm — Total number
of unicast frames (addressed to this specific adapter card) which
were successfully received over the medium at normal priority and
forwarded to an upper layer protocol such as IP. This includes link
training frames received from the 100VG-AnyLAN hub. It does not
include unicast frames received but dropped for any reason. The
maximum printable value of this 64-bit field is 17 digits, or about
99 million billion frames. In the previous example, 2.07 million
unicast frames were received at normal priority and forwarded to
upper layers.
Receives hipri — Total number
of unicast frames (addressed to this specific adapter card) which
were successfully received over the medium at high (demand) priority
and forwarded to an upper layer protocol such as IP. This includes
unicast frames for which normal priority was originally requested
by the sender, but which were later automatically priority-boosted
by the 100VG-AnyLAN network. It does not include unicast frames
received but dropped for any reason. The maximum printable value
of this 64-bit field is 17 digits, or about 99 million billion frames.
In the previous example, no frames have been received at high priority.
Recv broadcast norm — Total
number of frames addressed to a broadcast address which were successfully
received over the medium at normal priority and forwarded to an
upper layer protocol such as ARP. This does not include broadcast
frames received but dropped for any reason. The maximum value of
this 64-bit field is 17 digits, or about 99 million billion frames.
In the previous example, 47.1 million broadcast frames were received
at normal priority and forwarded to upper layers.
Recv broadcast hipri — Total
number of frames addressed to a broadcast address which were successfully
received over the medium at high (demand) priority and forwarded
to an upper layer protocol such as ARP. This includes broadcast
frames for which normal priority was originally requested by the
sender, but which were later automatically priority-boosted by the
100VG-AnyLAN network. It does not include broadcast frames received
but dropped for any reason. The maximum printable value of this
64-bit field is 17 digits, or about 99 million billion frames. In
the previous example, no frames have been received at high priority.
Recv multicast norm — Total
number of frames addressed to a multicast address which were successfully
received over the medium at normal priority and forwarded to an
upper layer protocol such as PROBE. This does not include multicast
frames received but dropped for any reason. Upper layer protocols
register desired multicast addresses with the link driver during
initialization. The maximum printable value of this 64-bit field
is 17 digits, or about 99 million billion frames. In the previous
example, 1.30 million multicast frames were received at normal priority
and forwarded to upper layers.
Recv multicast hipri — Total
number of frames addressed to a multicast address which were successfully
received over the medium at high (demand) priority and forwarded
to an upper layer protocol such as PROBE. This includes multicast
frames for which normal priority was originally requested by the
sender, but which were later automatically priority-boosted by the
100VG-AnyLAN network. It does not include multicast frames received
but dropped for any reason. Upper layer protocols register desired
multicast addresses with the link driver during initialization.
The maximum printable value of this 64-bit field is 17 digits, or
about 99 million billion frames. In the previous example, no frames
have been received at high priority.
Receives no error — Total
number of frames the adapter card reports it successfully received
over the medium. These adapter card statistics are periodically
read, and are accumulated by the link driver. This includes both
normal and high (demand) priority frames. It does not include any
frames the adapter card detected errors against. The total should
approximate the sum of all frames forwarded to upper layer protocols,
plus all frames dropped for any reason. The maximum printable value
of this 64-bit field is 17 digits, or about 99 million billion frames.
In the previous example, 6.64 million frames were received successfully
by the adapter card, then either forwarded or dropped.
Recv dropped: addr — Total
number of frames received by the adapter card, but dropped because
no upper layer protocol had requested future reception of those
frames, or because that protocol unbound itself from the link while
the received frame was still in motion. Older, intelligent adapter
cards can invisibly receive and drop these frames, often without
ever reporting them as statistics. But today's adapters
are not intelligent, and require link driver involvement. For users
unfamiliar with seeing it, this statistic may seem excessive. But
it is important because it gives an indication of the amount of
unnecessary traffic present on the network segment to which the
adapter card is connected. High values may indicate a need to resegment
the network, since systems and their adapters are spending a large
amount of time and resources recognizing and dropping frames they
do not care to see. High volumes of such traffic can also limit network
bandwidth. The maximum printable value of this 64-bit field is 17
digits, or about 99 million billion frames. In the previous example, out
of 66.4 million frames received, 16.0 million have been dropped based
on address: about 24% of all frames received are then being dropped.
This level would be considered typical or perhaps a little high.
Recv dropped: buffer — Total
number of frames received from the adapter card, but dropped because
no data buffers were available from the upper layer protocol requesting
to receive these frames. This is a relatively common occurrence,
amounting to flow control for all protocols sharing those buffers.
Many protocols include built-in mechanisms for detecting lost frames
and requesting their retransmission from the remote side. The maximum
value of this 32-bit field is 2147483647. In the previous example,
out of 66.4 million frames received, 262 have been dropped for lack
of buffer resources; any similar level would be considered normal.
Recv dropped: dma — The link
driver design now queues frames under conditions of low DMA resources,
so this statistic is now obsolete, should never contain a nonzero
value, and may be deleted in a future release.
Recv dropped: other — Sum
total number of frames received from the adapter card, but dropped
because: an upper layer protocol error was returned; the required
address format was not supported; the frame arrived while the link
driver was in an unusual state; or for perfect multicast filtering
reasons. The maximum value of this 32-bit sum is 2147483647. In
the previous example, 24785 frames have been dropped for one or
more of the reasons listed; this number would be considered high,
and further investigation might be needed if it appears to be impacting
any applications.
Secs since clear — The number of seconds elapsed since statistics
were last reset via the LINKCONTROL linkname;
STATUS=RESET command. This gives the sample time over which the displayed
statistics have been collected. Per-time-unit figures may then be calculated
if desired. The maximum value of this 32-bit field is 2147483647,
or about 68 years.
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