IST2274I

Explanation
 VTAM® issues
this message as part of a group of messages in response to a  DISPLAY
TOPO,LIST=TDUDIAG summary command.  Possible message groups follow: This message group is issued if you allow the FORMAT command to
default or you specify FORMAT=SHORT:   IST350I  DISPLAY TYPE = TDU DIAGNOSTICS
 IST2274I TDU DIAGNOSTIC SUMMARY:
 IST1780I TOPOLOGY RESOURCES WITH MOST FREQUENT TDU ACTIVITY
 IST2308I   THAT HAVE SAVED TDUDIAG RSN UPDATES              
 IST2275I TDU INFORMATION SINCE LAST RESET ON date AT time
 IST2290I TDUDIAG START OPTION = tdudiag_value
[IST2283I NO TDUDIAG RSN UPDATES EXIST]
[IST2276I NO CORRUPTION OF TOPOLOGY CONTROL VECTORS DETECTED]
[IST924I -------------------------------------------------------------]
[IST2277I POSSIBLE CORRUPTION OF TOPOLOGY CONTROL VECTORS DETECTED]
[IST2278I SINCE VTAM START ON start_date AT start_time]
[IST2284I   FOR THE FOLLOWING NODES AND TGS]
[IST2279I CP NAME           DESTINATION CP    TGN    TIME DETECTED]
[IST2280I cp_name           destination_cp    tgn  date_detected time_detected]
⋮
[IST2301I num OF total TOPOLOGY RESOURCES DISPLAYED]
[IST924I -------------------------------------------------------------] 
[IST2283I NO TDUDIAG RSN UPDATES EXIST]
[IST2286I TDUS RECEIVED:]
[IST1777I CP NAME           RSN      DESTINATION CP    TGN ACC   REJ]
[IST1778I cp_name           rsn      destination_cp    tgn count1 count2]
⋮
[IST2301I num OF total TOPOLOGY RESOURCES DISPLAYED]
[IST924I -------------------------------------------------------------]
[IST2287I TDUS SENT:]
[IST2288I CP NAME           RSN      DESTINATION CP    TGN SENT  REC]
[IST1778I cp_name           rsn      destination_cp    tgn count1 count2]
⋮
[IST2301I num OF total TOPOLOGY RESOURCES DISPLAYED]
[IST924I -------------------------------------------------------------]
[IST2289I RESOURCE SEQUENCE NUMBERS UPDATED BY THIS NODE:]
[IST2292I CP NAME           RSN      DESTINATION CP    TGN  UPDATED]
[IST2293I cp_name           rsn      destination_cp    tgn  updated]
⋮
[IST2301I num OF total TOPOLOGY RESOURCES DISPLAYED]
 IST314I END   

If you specify FORMAT=LONG on the DISPLAY TOPO command, the display
sections for TDUs received, TDUs sent, and RSNs updated by this node
are replaced with the following:  [IST924I -------------------------------------------------------------] 
[IST2283I NO TDUDIAG RSN UPDATES EXIST]
[IST2286I TDUS RECEIVED:]
[IST2357I CP NAME            RSN         DESTINATION CP     TGN]
[IST2358I cp_name            rsn         destination_cp     tgn]
[IST2353I   ACCEPTED = accepted     REJECTED = rejected]      
⋮
[IST2301I num OF total TOPOLOGY RESOURCES DISPLAYED]
[IST924I -------------------------------------------------------------]
[IST2287I TDUS SENT:]
[IST2357I CP NAME            RSN         DESTINATION CP     TGN]
[IST2358I cp_name            rsn         destination_cp     tgn]
[IST2352I   SENT     = sent         RECEIVED = received]
⋮
[IST2301I num OF total TOPOLOGY RESOURCES DISPLAYED]
[IST924I -------------------------------------------------------------]
[IST2289I RESOURCE SEQUENCE NUMBERS UPDATED BY THIS NODE:]
[IST2357I CP NAME            RSN         DESTINATION CP     TGN]
[IST2358I cp_name            rsn         destination_cp     tgn]
[IST2291I   UPDATED  = updated]
⋮
[IST2301I num OF total TOPOLOGY RESOURCES DISPLAYED]
 IST314I END

 IST350I  This message identifies the type of information in the display
and is always TDU DIAGNOSTICS for this message group.

 IST1777I  This is a header message for the information about topology resources
in the TDUs that were received most frequently and that have TDUDIAG
resource sequence number (RSN) update information saved in the topology
database.  The topology resources are displayed in the IST1778I messages
that follow.  These messages are displayed when FORMAT=SHORT is specified
or the default FORMAT value is taken.
ACC is the abbreviation for ACCEPTED. 
REJ is the abbreviation for REJECTED.

 IST1778I  One IST1778I is issued for each topology resource that is displayed
in a subgroup when the FORMAT=SHORT operand is specified or the default
FORMAT value is taken. 
The NUM operand can be specified on the DISPLAY command to limit
the number of topology resources that are displayed.  The default
value is 10 and the maximum value is 50.  If the number of topology
resources on the list since the TDU information and TDU counters were
last reset is smaller than the number requested on the display command,
the number of IST1778I messages that are displayed in the subgroup
will be smaller than the NUM value that was specified.
cp_name is the network-qualified CP name of
the node, if the resource that is displayed is a node. If the resource
that is displayed is a TG, cp_name is the network-qualified
CP name of the TG origin node. 
rsn is the resource sequence number (RSN) expressed
in decimal.
destination_cp is the network-qualified CP
name of the TG's destination node if the resource that is displayed
is a TG. If the resource is a node, ***NA*** is displayed.
tgn is the transmission group number that is
associated with the TG that is displayed. If the resource is a node,
NA is displayed.
If the subgroup displays the information about topology resources
in the TDUs that were received most frequently: count1 is the total number of inbound TDUs
that were accepted for this resource at the time that the displayed
TDU was received.  Inbound TDUs are accepted when they contain new
information that causes the resource record to be updated.
count2 is the total number of inbound TDUs
that were rejected for this resource at the time that the displayed
TDU was received.  Inbound TDUs are rejected when they contain inconsistent
information that causes outbound TDUs to be sent as corrections.

If the subgroup displays the information about topology resources
in the TDUs that were sent most frequently: count1 is the total number of outbound TDUs
that were sent for this resource at the time that the displayed TDU
was sent.
count2 is the total number of inbound TDUs
that were received for this resource at the time that the displayed
TDU was sent.

 Tip: A RSN value of ******** or TDU counter values
of ***** indicates that the values are greater than the available
space for those values to be displayed in message IST1778I.  You can
enter the command with the FORMAT=LONG operand  to display these values
in a format that includes two lines of output for each resource. 
 IST1780I,
IST2308I  These messages indicate that the TDU diagnostic information is
about topology resources that were included in topology database updates
(TDUs) most frequently, and that have saved TDUDIAG resource sequence
number (RSN)  update information.

 IST2274I  This is a header message for TDU diagnostic summary information.

 IST2275I This message contains the date and time when all the TDU information
and TDU counters were reset.  All TDU information and TDU counters
are reset every 24 hours when garbage collection runs, or when a DISPLAY
NET,TOPO,LIST=TDUINFO,CLEAR=YES or a DISPLAY NET,TOPO,LIST=TDUDIAG,CLEAR=YES
command is entered.   See DATE and TIME formats for
information about the date and time values.

 IST2276I  This message indicates that no corruption of topology control
vectors was detected since VTAM was
started.

 IST2277I  This is a header message for a message subgroup that displays
information about topology resources that have control vectors in
the topology database that have possibly been corrupted.  
Because the topology control vectors contain the resource sequence
number (RSN) for a node or TG, which determines the processing of
a TDU, it is possible that control vector corruption could cause a
TDU war.  The most probable cause of control vector corruption is
a storage overlay.

 IST2278I  This message displays the date and time that VTAM was started.  See DATE and TIME formats for information about the date and time values.
Unlike the lists of topology resources in the TDUs that were
received or sent most frequently, or with RSNs that were updated by
this node, the list of topology resources with possible topology control
vector corruption is never cleared and includes any possible corruption
detection since the start of VTAM.

 IST2279I  This is a header message for the information about topology resources
with possible topology control vector corruption that is displayed
in the IST2280I messages that follow.  

 IST2280I  One IST2280I is displayed for each topology resource that has
control vectors that have possibly been corrupted. 
Information about possible corrupted control vectors is maintained
from the start of VTAM and
is not deleted when TDU information is reset.  All topology resources
with possible corrupted control vectors are displayed in this subgroup,
regardless of the reset of TDU information.
The NUM operand can be specified on the DISPLAY command to limit
the number of topology resources that are displayed.  The default
value is 10 and the maximum value is 50.  If the number of topology
resources on the list since the start of VTAM is smaller than the number requested on
the display command, the number of IST2280I messages that are displayed
in the subgroup will be smaller than the NUM value that was specified. 
cp_name is the network-qualified CP name of
the node, if the resource that is displayed is a node. If the resource
that is displayed is a TG, cp_name is the network-qualified
CP name of the TG origin node. 
destination_cp is the network-qualified CP
name of the TG's destination node if the resource that is displayed
is a TG. If the resource that is displayed is a node, ***NA*** is
displayed.
tgn is the transmission group number that
is associated with the TG that is displayed.  If the resource is a
node, NA is displayed.
Time detected is the date and time possible corruption of control
vectors for the topology resource was detected.  See DATE and TIME formats for information about the date and time values.

 IST2283I  This message is displayed when no TDUDIAG RSN update information
exists for any of the topology resources that have been received,
sent, or had RSNs updated since the TDU information and TDU counters
were last reset.  Message IST2275I displays the date and time of the
last reset.

 IST2284I  This message indicates that possible topology control vector
corruption was detected for a node or TG.

 IST2286I  This is a header message for message subgroups that display information
about topology resources in the TDUs that were received in inbound
TDUs most frequently and have TDUDIAG RSN update information saved
in the topology database.
The first topology resource that is displayed in the subgroup
is the resource with the most frequent TDU activity.  The last topology
resource that is displayed in the subgroup is the resource with the
least frequent TDU activity.

 IST2287I  This is a header message for message subgroups that display information
about topology resources in the TDUs that were sent most frequently
and have TDUDIAG RSN update information saved in the topology database.
The first topology resource that is displayed in the subgroup
is the resource with the most frequent TDU activity.  The last topology
resource that is displayed in the subgroup is the resource with the
least frequent TDU activity.

 IST2288I  This is a header message for the information about topology resources
in the TDUs that were sent most frequently and have TDUDIAG RSN update
information saved in the topology database.  The topology resources
are displayed in the IST1778I messages that follow.  These messages
are displayed when FORMAT=SHORT is specified or the default FORMAT
value is taken.
REC is the abbreviation for RECEIVED.

 IST2289I  This is a header message for information about topology resources
with RSNs that were updated by this node  and that have TDUDIAG RSN
update information saved in the topology database.
The first topology resource that is displayed in the subgroup
is the resource with a RSN that was updated most frequently.  The
last topology resource that is displayed in the subgroup is the resource
with a RSN that was updated least frequently. 

 IST2290I  tdudiag_value is the user-defined TDUDIAG start
option value, specified on the START command or in the start list,
 and  specifies when TDU diagnostic information is included with node
or TG control vectors within a TDU.  See the TDUDIAG
start option information in z/OS Communications Server: SNA Resource Definition
Reference. Possible values can be one of the following: A decimal value in the range of 1-65535
This is a threshold number of times that this network node has
updated the resource sequence number (RSN) for a topology resource
since the last time that TDU information was reset.  When this threshold
value is reached for a node or TG, TDU diagnostic information is included
in the outbound TDU if the RSN is updated.
ALWAYS
TDU diagnostic information is always appended with the topology
control vectors included in a TDU for a topology resource when the
RSN for that resource is updated by this network node.
NEVER
TDU diagnostic information is never appended with the topology
control vectors included in a TDU.

 IST2291I  This message follows message IST2358I and this message pair displays
the information about topology resources that have a RSN that was
updated by this node and have TDUDIAG RSN update information saved
in the topology database, when the FORMAT=LONG operand is specified. 
updated is the number of times the topology
resource had been updated at the time of the last RSN update.

 IST2292I  This is a header message for the information about topology resources
with RSNs that were updated by this node and that have TDUDIAG RSN
update information saved in the topology database.  The topology resources
are displayed in the IST2293I messages that follow.  These messages
are displayed when FORMAT=SHORT is specified or the default FORMAT
value is taken.

 IST2293I  One IST2293I is issued for each topology resource that has a
RSN that was updated by this node and has TDUDIAG RSN update information
saved in the topology database.  The first IST2293I message in this
message subgroup describes the topology resource whose RSN was updated
by this node most frequently.
The NUM operand can be specified on the DISPLAY command to limit
the number of topology resources that are displayed.  The default
value is 10 and the maximum value is 50.  If the number of topology
resources on the list since the TDU information and TDU counters were
last reset is smaller than the number requested on the display command,
the number of IST2293I messages that are displayed in the subgroup
will be smaller than the NUM value that was specified. 
cp_name is the network-qualified CP name of
the nod, if the resource that is displayed is a node. If the resource
that is displayed is a TG, cp_name is the network-qualified
CP name of the TG origin node. 
rsn is the updated RSN expressed in decimal. 
destination_cp is the network-qualified CP
name of the TG's destination node if the resource that is displayed
is a TG. If the resource is a node, ***NA***  is displayed. 
tgn is the transmission group number that
is associated with the TG that is displayed. If the resource is a
node, NA is displayed.
updated is the number of times that the topology
resource has been updated at the time of the last RSN update.

 Tip: A RSN value of ******** or update counter
value of ***** indicates the value is greater than the available space
for the value to be displayed in message IST2293I.  You can enter
the command with the FORMAT=LONG operand  to display these values
in a format that includes two lines of output for each resource.
 IST2301I  This message displays the number of topology resources that are
in a message subgroup.
num is the total number of topology resources
that are displayed.
total is the total number of topology resource
records that are on the displayed list.

 IST2352I  This message follows message IST2358I when the FORMAT=LONG operand
is specified.  This message pair displays the information about topology
resources in the TDUs that were sent most frequently and have TDUDIAG
RSN update information saved in the topology database. 
sent is the total number of TDUs that were
sent for this resource at the time that the displayed TDU was sent. 
received is the total number of TDUs that
were received for this resource at the time that the displayed TDU
was sent.

 IST2353I  This message follows message IST2358I when the FORMAT=LONG operand
is specified.  The message pair displays the information about topology
resources in the TDUs that were received most frequently and have
TDUDIAG RSN update information saved in the topology database. 
accepted is the total number of inbound TDUs
that were accepted for this resource at the time that the displayed
TDU was received.  Inbound TDUs are accepted when they contain new
information that causes the resource record to be updated.
rejected is the total number of inbound TDUs
that were rejected for this resource at the time that the displayed
TDU was received.  Inbound TDUs are rejected when they contain inconsistent
information that causes outbound TDUs to be sent as corrections.

 IST2357I  This is a header message for the information about topology resources
that is displayed in message pairs when FORMAT=LONG is specified.
The information is displayed in three sections:  topology resources in the TDUs that were received most frequently
and have TDUDIAG RSN update information saved in the topology database
topology resources in the TDUs that were sent most frequently
and have TDUDIAG RSN update information saved in the topology database
topology resources with RSNs that were updated by this node and
have TDUDIAG RSN update information saved in the topology database

 IST2358I  This is the first of two messages that display the information
about a topology resource when the FORMAT=LONG operand is specified. 
The NUM operand can be specified on the DISPLAY command to limit
the number of topology resources that are displayed.  The default
value is 10  topology resources, or message pairs, and the maximum
value is 50.  If the number of topology resources on the list since
the last TDU count reset is smaller than the number requested on the
display command, the number of topology resources that are displayed
in the subgroup will be smaller than the NUM value that was specified.
cp_name is the network-qualified CP name of
the node if the resource that is displayed is a node. If the resource
that is displayed is a TG, cp_name is the network-qualified
CP name of the TG origin node. 
rsn is the resource sequence number (RSN)
expressed in decimal.
destination_cp is the network-qualified CP
name of the TG's destination node if the resource that is displayed
is a TG. If the resource is a node, ***NA*** is displayed . 
tgn is the transmission group number that
is associated with the TG that is displayed. If the resource is a
node, NA is displayed.

System action
 Processing continues.

Operator response
 If you are displaying TDU diagnostic information
because of performance  degradation of the APPN network, use the information
about display TDU information in z/OS Communications Server: SNA Diagnosis Vol
1, Techniques and Procedures, and do the following:
 Repeat the display several times to see if there is a pattern
of excessive TDU activity for a topology resource.
Enter the DISPLAY NET,TOPO,LIST=TDUINFO,SCOPE=ACTIVITY command
to see the topology resources that have the most frequent TDU activity.
If a node or TG is identified that has excessive TDU activity,
the following displays might  provide information about the network
nodes that are causing the performance degradation (TDU war):  DISPLAY NET,TOPO,LIST=TDUDIAG provides a summary of nodes and
TGs that have saved TDU diagnostic information.
DISPLAY NET,TOPO,LIST=TDUDIAG,ID=cp_name provides
details about the saved TDU diagnostic information for a node. 
DISPLAY NET,TOPO,LIST=TDUDIAG,ORIG=orig_cp,DEST=dest_cp,TGN=tgn provides
details about saved TDU diagnostic information for a TG.  

If you can identify the network nodes that are involved in the
TDU war, bring down the  CP-CP sessions from one of the network nodes
involved to all other network  nodes in the network or subnetwork. 
If you cannot stop the TDU war, save the system log and request
a dump for  problem determination.  Contact the system programmer.

 Tip: On the DISPLAY NET,TOPO,LIST=TDUDIAG summary
command output, a RSN value of ******** or TDU counter values of *****
indicates that the value is greater than the available space for the
value to be displayed in message IST1778I or IST2293I.  You can clear
the TDU counters, but not the RSN, with the CLEAR=YES operand specified
on either the DISPLAY TOPO,LIST=TDUINFO command or the DISPLAY TOPO,LIST=TDUDIAG
summary command.  Alternately, you can enter the command with the
FORMAT=LONG operand  to display these values in a format that includes
two lines of output for each resource.

System programmer response
 Take the following actions:  If the operator provides output from the DISPLAY NET,TOPO,LIST=TDUINFO
and the DISPLAY NET,TOPO,LIST=TDUDIAG commands, use the information
about display TDU information in z/OS Communications Server: SNA Diagnosis Vol
1, Techniques and Procedures to analyze the TDU activity.   If possible,
identify the topology resource that is in contention and the network
nodes that are involved in the TDU war. 
If you have access to IBMLink, search for known problems in this
area. If no  applicable matches are found, report the problem to IBM® by using the Electronic  Technical
Report (ETR) option on IBMLink.  
If you do not have access to IBMLink, report the problem to the IBM software  support center. 

User response
 Not applicable.

Problem determination
 See the system programmer response.

Source
 z/OS® Communications
Server SNA

Module
 You can display the module that issues a SNA message
in the message by setting the MSGMOD start option to YES.  See Adding the originating module to the message text for more information about the MSGMOD
start option.

Routing code
 2

Descriptor code
 5

Automation
 Not recommended.

Example
  The following
is an example of the display output from a DISPLAY NET,TOPO,LIST=TDUDIAG,NUM=5,FORMAT=SHORT
command: IST350I  DISPLAY TYPE = TDU DIAGNOSTICS
IST2274I TDU DIAGNOSTIC SUMMARY:
IST1780I TOPOLOGY RESOURCES WITH MOST FREQUENT TDU ACTIVITY
IST2308I   THAT HAVE SAVED TDUDIAG RSN UPDATES
IST2275I TDU INFORMATION SINCE LAST RESET ON 01/29/10 AT 11:43:05
IST2290I TDUDIAG START OPTION = 1000
IST2276I NO CORRUPTION OF TOPOLOGY CONTROL VECTORS DETECTED
IST924I -----------------------------------------------------------
IST2286I TDUS RECEIVED:
IST1777I CP NAME           RSN      DESTINATION CP    TGN ACC   REJ
IST1778I NETA.SSCP2A       6        NETA.SSCP1A       21  2     0
IST1778I CNRA.LVRN4A       2        NETA.SSCP2A       21  1     0
IST1778I NETA.SSCP2A       2        CNRA.LVRN4A       21  1     0
IST1778I NETA.SSCPAA       4        NETA.SSCP1A       21  1     0
IST1778I NETA.SSCPAA       2        ***NA***          NA  1     0
IST2301I 5 OF 6 TOPOLOGY RESOURCES DISPLAYED
IST924I -----------------------------------------------------------
IST2287I TDUS SENT:
IST2288I CP NAME           RSN      DESTINATION CP    TGN SENT  REC
IST1778I NETA.SSCP2A       6        NETA.SSCP1A       21  3     3
IST1778I NETA.SSCP1A       6        NETA.SSCP2A       21  3     1
IST1778I NETA.SSCP2A       2        ***NA***          NA  2     1
IST1778I NETA.SSCP1A       2        ***NA***          NA  2     0
IST1778I CNRA.LVRN4A       2        NETA.SSCP2A       21  1     1
IST2301I 5 OF 11 TOPOLOGY RESOURCES DISPLAYED
IST924I -----------------------------------------------------------
IST2289I RESOURCE SEQUENCE NUMBERS UPDATED BY THIS NODE:
IST2292I CP NAME           RSN      DESTINATION CP    TGN  UPDATED
IST2293I NETA.SSCP1A       6        NETA.SSCP2A       21   1
IST2293I CNRA.LVRN4A       2        NETA.SSCP1A       21   1
IST2293I NETA.SSCP1A       2        CNRA.LVRN4A       21   1
IST2301I 3 OF 3 TOPOLOGY RESOURCES DISPLAYED
IST314I END