• DISPLAY,TOPO,ORIG=cpname,DEST=cpname
• DISPLAY,TOPO,ORIG=cpname,TGN=tgn

IST1299I  TRANSMISSION GROUPS ORIGINATING AT CP cpname
IST1357I                                                  CPCP
IST1300I  DESTINATION CP    TGN      STATUS   TGTYPE      VALUE WEIGHT
IST1301I  destcpname        tgn      status   tgtype      cpval weight

• This is a header message for information about a TG that originates in cp_name.
• The cp_name value is the network-qualified CP name of the origin node of the TG.

• These are header messages for information displayed in message IST1301I.

• The destcpname value is the network-qualified CP name of the TG destination node.
• The tgn value is the TG number. Possible values are 0-255.
• The status value is the current state of the TG. Possible values are:

  OPER

  The TG is operational.

  INOP

  The TG is not operational.

  QUIES

  The TG is quiescent.

  Tip: The status value for an intercluster TG or a TG to a branch extender will always be QUIES when displayed in a non-owning node. The owning node of a TG is the node where the TG originates (origin node).

  If the TG is ready for garbage collection, /G is appended to the end of the status value.

• The tgtype value is the TG type. Possible values are:

  BRANCH

  The TG is a branch extender. The BRANCH tgtype can be used by IBM® Communications Server for Data Center Deployment on Linux. For more information about this function, see IBM Communications Server for Linux, Quick Beginnings, GC31-6768-04.

  ENDPT

  The TG is an endpoint TG. If the origin node or destination node is an EN, then the TG is an endpoint TG.

  ENDPT VRTG

  The TG is an endpoint VR-based TG (VRTG). A VRTG connects two APPN-capable VTAM nodes through a subarea network. A VRTG, although it creates the appearance of APPN, always represents underlying subarea connectivity. If the origin node or destination node is an EN, then the TG is an endpoint VRTG.

  INTERM

  The TG is an intermediate routing TG. An intermediate routing TG represents an NN to NN or NN to virtual routing node (VRN) connection.

  INTERM VRTG

  The TG is an intermediate routing VRTG. A VRTG connects two APPN-capable VTAM nodes through a subarea network. A VRTG, although it creates the appearance of APPN, always represents underlying subarea connectivity. An intermediate routing VRTG represents an NN to NN connection.

  INTERCLUST

  The TG is an intercluster (ICL) or intersubnet link (ISL) TG. These TGs are connections between border nodes or non-native nodes.

• The cpval value indicates whether this connection supports CP-CP sessions. Possible values are:

  YES

  The connection supports CP-CP sessions. This is not an indication that a CP-CP session is active across the TG.

  NO

  The connection does not support CP-CP sessions.

• The weight value represents the actual weight of TG tgn as calculated by VTAM using the TG, the TG profile, and the class of service (CoS) definitions. The value of 32767 is displayed when a TG is not operational or does not meet the CoS requirements specified by the APPNCOS parameter in the DISPLAY TOPO command.
  • The weight of TG tgn is a measure of the relative desirability of choosing that resource in the route selection process and is 0-255 or 32767.

  • See the APPN transmission group profile and the APPN Class of Service definitions in z/OS Communications Server: SNA Resource Definition Reference for more information about coding TG profiles and APPN Class of Service definitions.

IST1302I                    CAPACITY PDELAY   COSTTIME    COSTBYTE
IST1303I                    capacity pdelay   costtime    costbyte

• This is a header message for information displayed in message IST1303I.

• The capacity value is a user-defined value that can be specified on the GROUP, LINE, PU, or TGP definition statements. This value represents the number of bits per second that the link will transmit. Possible values are:

  nnnnK

  The valid range for nnnn is 1-1000 expressed in kilobits.

  nnnnM

  The valid range for nnnn is 1-1000 expressed in megabits.

  nnnnG

  The valid range for nnnn is 1-1000 expressed in gigabits.

  See the information about the CAPACITY operand in z/OS Communications Server: SNA Resource Definition Reference.

• The pdelay value (propagation delay) is a user-defined value that can be specified on the GROUP, LINE, PU, or TGP definition statements. This value represents the time needed for a signal to travel from one end of the link to the other. Possible values are:

  NEGLIGIB

  Less than .48 milliseconds.

  TERRESTR

  Between .48 and 49.151 milliseconds

  PACKET

  Between 49.152 and 245.76 milliseconds.

  LONG

  Greater than 245.76 milliseconds.

  See the information about the PDELAY operand in z/OS Communications Server: SNA Resource Definition Reference.

• The costtime value is a user-defined value that can be specified on the GROUP, LINE, PU, or TGP definition statements. This value indicates the cost of the line or node per connect time.
  • Possible values are 0-255. Low values are less expensive than higher values.
  • See the information about the COSTTIME operand in z/OS Communications Server: SNA Resource Definition Reference.
• The costbyte value is a user-defined value that can be specified on the GROUP, LINE, PU, or TGP definition statements. This value indicates the cost of the line or node per byte sent.
  • Possible values are 0-255. Low values are less expensive than higher values.
  • See the information about the COSTBYTE operand in z/OS Communications Server: SNA Resource Definition Reference.

IST1304I                    SECURITY UPARM1   UPARM2      UPARM3
IST1305I                    security uparm1   uparm2      uparm3

• This is a header message for information displayed in message IST1305I.

• The security value is the user-specified value that can be specified on the GROUP, LINE, PU, or TGP definition statements. This value indicates the security level of the transmission group. Possible values are:

  ENCRYPT

  Link encryption used.

  GUARDED

  Guarded conduit, physical only.

  PUBLIC

  Public switched network.

  SECURE

  Secure conduit, not guarded.

  SHIELDED

  Guarded conduit, physical and radiation shielded.

  UNSECURE

  Not secure.

  UNDERGRO

  Underground cable, not guarded.

  See the information about the SECURITY operand in z/OS Communications Server: SNA Resource Definition Reference.

• The uparm1, uparm2, and uparm3 values are user-defined parameter values. The user determines the meaning of these values, and the valid range is 0-255.

  See the information about the UPARM1 operand, the UPARM2 operand, and the UPARM3 operand in z/OS Communications Server: SNA Resource Definition Reference.

IST1736I                    PU NAME
IST1737I                    puname

• This is a header message for information displayed in message IST1737I.

• The puname value is the name of the physical unit.

IST2241I                                                  TIME  ISL
IST1163I                    RSN               HPR         LEFT  WEIGHT
IST1164I                    rsn               hpr         time  isl_wgt

• This is a header message for information displayed in message IST1164I.

• The rsn value is the RSN of the transmission group (TG) tgn expressed in decimal. The tgn is displayed in message IST1301I.
  • Displaying the RSN for a resource provides information about VTAM's current knowledge of that resource.
  • For example, if a display of a resource from two different VTAMs indicates different RSNs for the same resource, one VTAM might have backlevel information. This mismatch might indicate a problem.
• The hpr value indicates whether the TG is allowed to use Rapid Transport Protocols (RTP). Possible values are:

  YES

  The TG is allowed to use RTP. This is not an indication that RTP is used across the TG.

  NO

  The TG is not allowed to use RTP.

  For more information about the hpr value, see the description of message IST1482I.

• The time value is the number of days remaining until the TG is removed from the topology database (garbage collected), if the TG is either inoperative or has an odd-numbered rsn value. An operational TG with an even-numbered rsn value will not be removed from the database until the origin node is removed from the database, or until a topology database update (TDU) is received with an indication that the TG should be removed.
• The isl_wgt value represents the actual weight used in route calculation of the TG tgn value when the TG originates in a border node and the destination is an Enterprise Extender (EE) global virtual routing node (GVRN). This is the weight of the TG when it is used in a session route calculation and the PLU node calculating the route is in another subnet. When the PLU node is in another subnet, this TG is being used as an intersubnet link (ISL). The weight is calculated by z/OS® Communications Server using the TG, the TG characteristics, and the class of service (CoS) definitions.
  • When the TG is used this way, a COSTBYTE value of 0 is temporarily changed to 1 to increase the weight of the TG, so the weight that is displayed in message IST1301I might be different than the ISL weight that is displayed in message IST1164I. If the existing COSTBYTE value that is assigned to the TG is not 0, no change is made, and the weight that is displayed in message IST1301I is the same as the ISL weight that is displayed in message IST1164I. When the TG is being used for routes that are calculated in the subnet that contains the TG, it is not being used as an ISL and the weight that is displayed in IST1301I is used. See the Route calculation and selection information in z/OS Communications Server: SNA Network Implementation Guide for more information about route calculation using EE global VRNs across network boundaries.
  • The weight of a TG is a measure of the relative desirability of choosing that resource in the route selection process. The isl_wgt value can be one of the following:
    • A value in the range of 0-255.
    • 32767 when a TG is not operational or does not meet the CoS requirements specified by the APPNCOS operand in the DISPLAY TOPO command.
    • *NA* when the APPNCOS operand is not specified on the DISPLAY TOPO command, or when the destination of the TG is not an EE GVRN.
• See the z/OS Communications Server: SNA Resource Definition Reference for more information about coding TG profiles and APPN Class of Service definitions.

• This message contains the date and time when all the TDU information and TDU counters were reset. The TDU information and TDU counters for a TG are reset every 24 hours when garbage collection runs, or when one of the following commands is entered:
  • DISPLAY NET,TOPO,LIST=TDUINFO,CLEAR=YES
  • DISPLAY NET,TOPO,LIST=TDUDIAG,CLEAR=YES
  • DISPLAY NET,TOPO,LIST=TDUDIAG,ORIG=cpname,DEST=destcpname,TGN=tgn,CLEAR=YES

  See DATE and TIME formats for information about the date and time values.

• This message indicates possible topology control vector corruption was detected for the TG. Because the topology control vectors contain the resource sequence number (RSN) for the TG, which determines how a TDU is processed, it is possible that control vector corruption could cause a TDU war. A TDU war is the endless exchange of TDUs in contention over the same topology resource, resulting in continuous performance degradation of the APPN network. Possible corruption is detected when the topology control vectors saved in the topology database for the TG being processed do not appear to be formatted correctly. The most probable cause of control vector corruption is a storage overlay.

IST2282I TDU COUNTS:
IST2352I   SENT     = sent         RECEIVED = received
IST2353I   ACCEPTED = accepted     REJECTED = rejected
IST2354I   IGNORED  = ignored

• This is a header message for topology database update (TDU) counts for this TG.

• This message displays counts of TDUs sent and received for this TG.
• The sent value is the number of TDUs about the TG that were sent since the last time that the TDU counts were reset.
• The received value is the number of TDUs about the TG that were received since the last time that the TDU counts were reset.

• This message displays counts of TDUs accepted and rejected for this TG.
• The accepted value is the number of TDUs about the TG that were accepted since the last time TDU counts were reset. The TDUs contain new information about the node and the topology database was updated.
• The rejected value is the number of TDUs about the TG that were rejected since the last time that the TDU counts were reset. The TDUs were rejected because the TDUs contain outdated information about the node. TDUs that were built from the local topology database information for the TG were sent as corrections.

• This message displays counts of TDUs ignored for this TG.
• The ignored value is the number of TDUs about the TG that were ignored since the last time that the TDU counts were reset. The TDUs were discarded because the TDUs contained no new information.