Start a communications trace

This action starts a communications trace for the specified line or network interface description.

Note: A communications trace can no longer be used to trace data on a network server description (*NWS). Use the communications trace function to trace data on either a specific line (*LIN) or a network interface description (*NWI).

If your system is multihomed, data might be sent on one interface and received on a different interface. In this situation, you should trace two communications lines to see packets that are sent and received.

To start a communications trace, follow these steps:

  1. Optional: To collect very large traces, you need to set the value for maximum storage size on the system. This value represents the amount of storage, in megabytes, that the communications trace function can allocate to contain the trace data from all traces run. This can only be done through the System Service Tools (SST) menu. To specify the value for maximum storage size, follow these steps:
    1. At the command line, type STRSST (Start System Service Tools).
    2. Type your Service Tools user ID and password.
    3. Select option 1 (Start a Service Tool).
    4. Select option 3 (Work with communications trace).
    5. Press F10 (Change size).
    6. For the New maximum storage size prompt, specify a sufficient amount of storage for the traces you collect, and press Enter.
    7. Press F3 (Exit) to exit System Service Tools.
  2. At the command line, type STRCMNTRC.
  3. For the Configuration object prompt, specify the name of the line, such as TRNLINE.
  4. For the Type prompt, specify the type of resource, either *LIN or *NWI.
  5. For the Buffer size prompt, specify a sufficient amount of storage for the anticipated volume of data. For most protocols, 8 MB is sufficient storage. For a 10/100 Ethernet connection, 16 MB through 1 GB is sufficient. If you are uncertain, specify 16 MB for the maximum amount of storage allowed for the protocol.
  6. For the Communications trace options prompt, specify *RMTIPADR if you want to limit the data collected to a trace of one remote interface. Otherwise, use the default value.
  7. For the Remote IP address prompt, specify the IP address associated with the remote interface to which the trace data will be collected.
The communications trace continues until one of the following situation occurs:
  • The ENDCMNTRC command is run.
  • A physical line problem causes the trace to end.
  • The Trace full prompt specifies *STOPTRC and the buffer becomes full.
Parent topic: Perform a communications trace
Next topic: End a communications trace