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HP OpenVMS System Management Utilities Reference Manual


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SHOW LINK

Displays the status and LAT characteristics of links on the local node.

Format

SHOW LINK [link-name]


Parameter

link-name

Specifies the name for a LAT data link. A link name can have up to 16 ASCII characters.

If you do not specify a link name, LATCP displays information about all links currently defined for the node.


Qualifiers

/BRIEF

Displays the device name and state of the link. This is the default display.

/COUNTERS

Displays the device counters kept for the link. The numbers displayed represent the values recorded since the last time the counters were reset (when the node first started or when the ZERO COUNTERS command was used).

Do not use the /BRIEF or /FULL qualifier with this qualifier.

The following table lists and describes counters common to both CSMA/CD (carrier sense, multiple access with collision detect) and FDDI (Fiber Distributed Data Interface) links:

Counter Description
Messages received The total number of messages received over the link.
Multicast messages received The total number of multicast messages received over the link.
Bytes received The total number of bytes of information received over the link.
Multicast bytes received The total number of multicast bytes received over the link.
System buffer unavailable The total number of times no system buffer was available for an incoming frame.
Unrecognized destination The total number of times a frame was discarded because there was no portal with the protocol enabled. This count includes frames received for the physical address only.
Messages sent The total number of messages sent over the link.
Multicast messages sent The total number of multicast messages sent over the link.
Bytes sent The total number of bytes of information sent over the link.
Multicast bytes sent The total number of bytes of multicast messages sent over the link.
User buffer unavailable The total number of times no user buffer was available for an incoming frame that passed all filtering.
Data overrun The total number of bytes lost on the link's device because the local node's input buffers were full. A nonzero value can indicate noisy lines, a bad device, a busy or poorly tuned system (not enough resources allocated), or a hardware problem with another device on the LAN connection.

The following table lists and describes receive errors common to both CSMA/CD and FDDI links. These errors, which are included in the display generated by the SHOW LINK/COUNTERS command, are represented by flags that indicate the error has occurred.

Flag Description
Block check error CRC error in packets received.
Framing error Received frames ended incorrectly.
Frame too long Frames received longer than length limits.
Frame status error CRC error on ring noticed by local FDDI station (FDDI only).
Frame length error Frame length too short (FDDI only).

The following table lists and describes transmit errors common to both CSMA/CD and FDDI links. These errors, which are included in the display generated by the SHOW LINK/COUNTERS command, are represented by flags that indicate the error has occurred.

Flag Description
Excessive collisions Frames failed to transmit because the collision limit of 16 was reached (CSMA/CD only).
Carrier check failures Indicates transceiver problem or short circuit in cable.
Short circuit Short circuit in cable.
Open circuit Open circuit in cable.
Frame too long Frames too long. Indicates a transmission problem in one of the portals using the link.
Remote failure to defer A remote station failed to defer frames transmission. Could indicate a misconfigured network.
Transmit underrun Transmission of a frame was too slow. Indicates a hardware controller error.
Transmit failure Frames failed to transmit.

The following table lists and describes link counters specific to CSMA/CD only:

Counter Description
Transmit CDC failure The total number of carrier detect check errors, that is, the number of times the local node failed to detect that another Ethernet station was already transmitting when the local node began transmitting.
Messages transmitted: Single collision---The total number of times a frame was successfully transmitted on the second attempt after a normal collision on the first attempt.

Multiple collision---The total number of times a frame was successfully transmitted on the third or later attempt after normal collisions on previous attempts.

Initially deferred---The total number of times a frame transmission was deferred on its first attempt. This counter is used to measure Ethernet contention with no collisions.

The following table lists and describes link counters specific to FDDI only:

Counter Description
Ring initializations initiated The total number of times a ring reinitialization was initiated by the link.
Ring initializations received The total number of times a ring reinitialization was initiated by some other link.
Directed beacons received The number of times the link detected the directed beacon process. Each invocation of the directed beacon process is counted only once.
Connections completed The number of times the station successfully connected to the concentrator.
Duplicate tokens detected The number of times a duplicate token was detected on the link.
Ring purge errors The number of times the ring purger received a token while still in the ring purge state.
LCT rejects Link Confidence Test rejects. Indicates a problem with communication between station and concentrator.
Elasticity buffer errors Elasticity buffer function errors. Indicates a station on the ring with a transmit clock out of tolerance.
MAC error count The number of times the Media Access Control (MAC) changed the E indicator in a frame from R to S.
Traces initiated The number of times the PC-trace process was initiated by the link.
Traces received The number of times the link was requested to perform the PC-trace process.
Ring beacons initiated The number of times the ring beacon process was initiated by the link.
Link errors The number of times the Link Error Monitor (LEM) detected an error in a received message. Slow counts are normal.
Duplicate address test failures The number of times the link address was a duplicate.
FCI strip errors The number of times a Frame Content Independent Strip operation was terminated by receipt of a token.
LEM rejects The number of times excessive LEM errors were encountered.
MAC frame count The total number of frames (other than tokens) seen by the link.
MAC lost count The total number of times a frame (other than a token) was improperly terminated.

/FULL

Displays the device name, state, and datalink address of the link and indicates whether the DECnet address is enabled.

Description

Displays information about the specified link or all links if you do not specify a link. Depending on the qualifier you use with the SHOW LINK command, you can display a link's device name, state, LAT datalink address, DECnet address, or counters.

Examples

#1

LATCP> SHOW LINK/FULL NETWORK_A
      

This command produces the following display of information about link NETWORK_A:


Link Name:     NETWORK_A               Datalink Address:  08-00-2B-10-12-E3
Device Name:   _ESA7:                  DECnet Address:    Disabled
Link State:    On

The display in this example gives the device name of link NETWORK_A and the device's hardware address. The link is in the On state.

#2

LATCP> SHOW LINK LINK_A/COUNTERS
      

This command produces the following display of counters for link LINK_A:


Link Name:    LINK_A
Device Name:  _ETA6:

Seconds Since Zeroed:            65535
Messages Received:            18582254     Messages Sent:             3550507
Multicast Msgs Received:      15096805     Multicast Msgs Sent:        413178
Bytes Received:             1994694325     Bytes Sent:              290838585
Multicast Bytes Received:   1528077909     Multicast Bytes Sent:     32637472
System Buffer Unavailable:        8724     User Buffer Unavailable:      6269
Unrecognized Destination:            0     Data Overrun:                    0

Receive Errors -                           Transmit Errors -
   Block Check Error:               No        Excessive Collisions:        No
   Framing Error:                   No        Carrier Check Failure:       No
   Frame Too Long:                  No        Short Circuit:               No
   Frame Status Error:              No        Open Circuit:                No
   Frame Length Error:              Yes       Frame Too Long:              No
                                              Remote Failure To Defer:     No
                                              Transmit Underrun:           No
                                              Transmit Failure:            No

CSMACD Specific Counters
------------------------

Transmit CDC Failure:                0

Messages Transmitted -
   Single Collision:             43731
   Multiple Collisions:          73252
   Initially Deferred:          164508

SHOW NODE

Displays the status and LAT characteristics of a node.

Format

SHOW NODE [node-name]


Parameter

node-name

Specifies the name of the node for which information is displayed. If you do not specify a node name, LATCP displays information about the local node.

You can also specify any valid wildcard for this parameter. For example, the SHOW NODE A* command displays the status and characteristics of all nodes that begin with the letter A.


Qualifiers

/ALL

Displays information about all nodes known to your local node. When you use this qualifier, specify the /FULL or /BRIEF qualifier as well. If you do not specify either the /FULL or /BRIEF qualifier, the default display will contain the node status and identification string (the display generated by the /BRIEF qualifier).

/BRIEF

Displays the node status and identification string. This is the default display if you specify the /ALL qualifier.

/COUNTERS

Displays the counters kept for the node. Do not use the /BRIEF or /FULL qualifier with this qualifier. The following table lists and describes the counters displayed with SHOW NODE/COUNTERS:
Counter Description
Messages received The total number of LAT messages received by the local node. If you specify a remote node with the SHOW NODE command, the number of LAT messages received from that remote node.
Messages transmitted The total number of LAT messages transmitted by the local node. If you specify a remote node with the SHOW NODE command, the number of LAT messages transmitted to that remote node.
Slots received The total number of LAT slots received by the local node. If you specify a remote node with the SHOW NODE command, the number of slots received from that remote node. A slot is a message segment that contains information corresponding to a single session.
Slots transmitted The total number of LAT slots transmitted by the local node. If you specify a remote node with the SHOW NODE command, the number of slots transmitted to that remote node.
Bytes received The total number of bytes of LAT information received by the local node. If you specify a remote node with the SHOW NODE command, the number of bytes received from that remote node.
Bytes transmitted The total number of bytes of LAT information transmitted by the local node. If you specify a remote node with the SHOW NODE command, the number of bytes transmitted to that remote node.
Multicast bytes received The total number of LAT multicast bytes received by the local node.
Multicast bytes sent The total number of LAT multicast bytes sent by the local node.
Multicast messages received The total number of LAT multicast messages received by the local node.
Multicast messages sent The total number of LAT multicast messages sent by the local node.
No transmit buffer The total number of times no buffer was available on the local node for transmission.
Multicast messages lost The total number of times LTDRIVER failed to process an inbound multicast message because of failed communication with the LATACP.
Multicast send failures The total number of times LTDRIVER failed to send a multicast message because of failed communication with the LATACP.
Controller errors The total number of times LTDRIVER failed to communicate with the data link controller driver.
Last controller error The most recent controller error.
Multiple node addresses The total number of times that a node announced itself with a physical address different from that in a previous announcement.
Duplicates received The total number of duplicate messages received by the local node. If you specify a remote node with the SHOW NODE command, the number of duplicate messages received from that remote node. This counter can indicate a system slowdown.
Messages retransmitted The total number of LAT messages that the local node retransmitted because they were not acknowledged by terminal servers (or nodes that support outgoing connections). If you specify a remote node with the SHOW NODE command, the number of messages retransmitted to that remote node.
Illegal messages received The total number of invalidly formatted LAT messages received by the local node. If you specify a remote node with the SHOW NODE command, the number of invalidly formatted messages the local node received from that remote node. Illegal messages are grouped into several types of protocol errors, which are listed at the end of this table.
Illegal slots received The total number of invalidly formatted LAT slots received by the local node. If you specify a remote node with the SHOW NODE command, the number of invalidly formatted slots the local node received from that remote node.
Solicitations accepted The total number of times a remote node accepted solicitations from the local node. If you specify a remote node with the SHOW NODE command, the number of accepted solicitations by that remote node.
Solicitations rejected The total number of times a remote node rejected solicitation from the local node. If you specify a remote node with the SHOW NODE command, the number of rejected solicitations by that remote node.
Solicitation failures The total number of times solicitations by the local node received no response.
Transmit errors The total number of times the data link failed to transmit a LAT message.
Last transmit error The most recent transmit error.
Virtual circuit timeouts The total number of times a LAT circuit to another node timed out, indicating that the remote node failed to send a valid message in the required time span. If you specify a remote node with the SHOW NODE command, the number of times the local node timed out from a connection to that remote node.
Discarded output bytes The total number of data bytes that were discarded because of an overflow of an internal buffer before the data could be output to an LTA device.
User data lost The total number of times LTDRIVER failed to allocate resources to buffer session data. User data is lost and the session is stopped.
Resource errors The number of times LTDRIVER was unable to allocate system resources.
Incoming solicits accepted The total number of times the local node accepted solicitations from other nodes.
Incoming solicits rejected The total number of times the local node rejected solicitations from other nodes.

The protocol errors that are counted as illegal messages are as follows. These protocol error messages are displayed if their associated counter is greater than zero:

  • Invalid message type received
  • Invalid start message received
  • Invalid sequence number received in start message
  • Zero-node index received
  • Node circuit index out of range
  • Node circuit sequence invalid
  • Node circuit index no longer valid
  • Circuit was forced to halt
  • Invalid server slot index
  • Invalid node slot index
  • Invalid credit field or too many credits used
  • Repeat creation of slot by server
  • Repeat disconnection of slot by master

/FULL

Displays the node's status, identification string, LAT protocol version, and the values of the node's characteristics. This is the default except when you specify the /ALL qualifier.

/STATUS

Displays statistical information for parameters such as the number of active circuits, sessions, and incoming queue entries. For each parameter, the display shows the current value, the highest value recorded, and the maximum value allowed.

Note that you can specify the /STATUS qualifier with the SHOW NODE command to display information about the local node only (for example, the command SHOW NODE /STATUS FOREIGN_NODE is not supported).


Description

This command displays information about a specified node or, if you do not specify a node name, about your local node. With the /ALL qualifier, the SHOW NODE command displays information about all nodes known to your local node. Depending on the qualifiers you use, you can display node counters, node status, the node identification string, the LAT protocol version running on the node, and the values set for the node's characteristics.

Examples

#1

LATCP> SHOW NODE/FULL

      

This command produces the following display of information about the local node:


Node Name:   LTC                            LAT Protocol Version:      5.2
Node State:  On
Node Ident:  LTC - Engineering Development

Incoming Connections:  Enabled              Incoming Session Limit:   None
Outgoing Connections:  Enabled              Outgoing Session Limit:   None
Service Responder:     Disabled

Circuit Timer (msec):        80             Keepalive Timer (sec):      20
Retransmit Limit (msg):      20             Node Limit (nodes):       None
Multicast Timer (sec):       20             CPU Rating:                  8
Maximum Unit Number:       9999

User Groups:     43, 73
Service Groups:  7-9, 13, 23, 40, 43, 45, 66, 72-73, 89, 120-127, 248-255

Service Name     Status      Rating  Identification
LTVMS            Available     31 D  .

This display indicates that the local node LTC is in the On state, which means LAT connections can be created on the node. LTC is running Version 5.2. of the LAT protocol. The identification of the node is "LTC - Engineering Development". Because this is the local node, the display does not give the address of a LAN device. Use the SHOW LINK command to find addresses of devices on the local node. The display for the status of remote nodes, as shown in Example 2, gives the Ethernet address of that node.

Both incoming and outgoing connections can be made on node LTC, the number of sessions is unlimited. The display indicates the values of various timers and lists the groups that are enabled. Users on the local node can access service nodes belonging to user groups 43 and 73. Locally offered services can be accessed by nodes belonging to the service groups listed.

The display indicates that the CPU rating of the local node is 8. The display shows that the node offers a service named LTVMS. This service is available and its rating is 31 D (dynamic). (An S would indicate the rating is static.)

#2

LATCP> SHOW NODE/FULL RWWUP
      

This command displays the following information about the remote node RWWUP:


Node Name:   RWWUP                          LAT Protocol Version:      5.2
Node State:  Reachable                      Address:     AA-00-04-00-11-10
Node Ident:  .

Incoming Connections:  Enabled

Circuit Timer (msec):        80
Multicast Timer (sec):       20

Service Groups:  7, 13, 42-43, 45, 66, 70-72, 75-82, 88-89

Service Name     Status      Rating  Identification
NAC              Available     28    .
SYSMGR           Available     28    .

This display indicates that remote node RWWUP is reachable and runs Version 5.2 of the LAT protocol. The display includes the Ethernet address of node RWWUP. Because incoming connections are enabled, you can connect to a service on node RWWUP, provided that your node belongs to one of the service groups listed in the display.

Node RWWUP offers two services: NAC and SYSMGR. Both are available.

#3

LATCP> SHOW NODE/ALL/BRIEF
      

This command displays the following information about all nodes known to the local node:


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