Troubleshooting MPTN Connections in Reflection for IBM

  • 7021598
  • 09-Jan-2003
  • 01-Apr-2018


Reflection for IBM version 11.0 through 14.x
IBM OS/400 version V3R1 and higher


This technical note offers troubleshooting tips on configuring your PC and AS/400 to support AnyNet or Multi-Protocol Transport Networking (MPTN) connections.

The MPTN transport type is used to connect to an AS/400 host and run APPC applications over TCP/IP using the EHNAPPC interface.


To use MPTN you need Windows Sockets compliant TCP/IP networking software on your PC. You also need version 3, release 1 (or higher) of the AS/400 operating system (OS/400) installed on your AS/400, with TCP/IP configured and active on the AS/400.

If you experience difficulty making an MPTN connection, try the following troubleshooting tips.

Verify that the Correct Software Is Installed

To ensure that you can make an MPTN connection, check both the IBM AS/400 host and your PC for the attributes listed below.

IBM Host Computer Requirements

The host system must be running OS/400 v3r1 or higher. However, there are known issues running MPTN on v3r1 and v3r6. These OS/400 releases need PTFs (program temporary fixes) applied to avoid sporadic session drops or hangs and to clean up disconnected MPTN sessions.

Any PTF included in the current cumulative fix package (CUM tape) is listed below with a corresponding CUM tape id. Apply the latest CUM tape first, and then apply the individual fixes listed below.


  • OS/400 (Product 5763SS1): SF29719, SF30468, SF29674, SF29515 (CUM tape C6100310), SF30360, SF31088, SF30795.
  • Microcode (Product 5763999): MF11777 (CUM tape C6100310), MF12182.


  • OS/400 (Product 5716SS1): SF29812, SF30533, SF30923, SF28795, SF30370, SF30629, SF30794.
  • Microcode (Product 5716999): MF11898 (C6107360), MF11642.

PC Requirements

For a successful MPTN connection, TCP/IP must be configured properly on your PC.

Try to Ping by Host Name

If you cannot ping the host computer by name, add the AS/400 to the TCP/IP stack's hosts file.

Try to Telnet by Host Name

If you cannot telnet to the host computer by name, troubleshoot the issue as if it were a telnet issue. In general, if you cannot telnet to the host, the problem lies with TCP/IP on your host computer, PC, or network.

Note: The host system name must match the AS/400 Local Control Point name. To verify the Local Control Point name, run DSPNETA from the OS/400 prompt.

Verify Settings in Session Setup

Check the System Name and Net ID in Session Setup.

Try to Create a New Device

In Session Setup, leave the Device Name blank and enter a new Location Name.

Check the Error Message in Reflection's Online Help

Record the exact text of the error message you receive and search for it in the "MPTN Error Messages" of Reflection's online help.

Check MPTN Support on the AS/400

To verify that MPTN support is enabled follow these steps:

  1. On the AS/400 command line, type DSPNETA. This opens the Display Network Attributes screen.
  2. Check that the value of Allow AnyNet Support is set to *YES. This value is usually found on the third page of the DSPNETA display. It should look like this:
Allow AnyNet support . . . . . . . : *YES

If you do not see this entry, let your system administrator know that MPTN is not enabled.

Verify that the APPC Controller Is Configured for AnyNet

To find out whether the APPS controller exists follow these steps:

  1. On the AS/400 command line, type WRKCTLD *CMN.
  2. Select 5 (Display) to check each controller's link type. The entry on the Display Controller Description screen should look like this:
Link type . . . . . . . . . . . . : *ANYNW

If no controller with a link type of *ANYNW exists, ask your system administrator to create one.

The Remote Control Point name on the Display Controller Description screen must be unique for each MPTN controller.

Verify that the APPC Controller Is Active

To determine that the APPC controller you are using for MPTN is active, follow these steps:

  1. On the AS/400 command line, type WRKCFGSTS. This opens the Work with Configuration Status screen.
  2. Find the name of the APPC controller that you identified in the section above.
  3. The status of this controller should be ACTIVE.

If you do not see this entry, let your system administrator know that the APPC controller for the MPTN is not active.

Note: The very first time you configure the APPC controller, it may display a status of VARIED ON, rather than ACTIVE.

Confirm that the MPTN Daemons Are Running on the AS/400

To confirm that MPTN daemons are running follow these steps:

  1. On the AS/400 command line, type NETSTAT.
  2. Select 3 (Work with TCP/IP Connection Status). You should see two entries that look like this:
* * APPCove > 000:00:08 Listen
* * APPCove > 000:28:36 *UDP

If you do not see these entries, let your system administrator know that MPTN daemons are not running on the AS/400.

  1. Move the cursor to the APPCove entry in the Local Port column.
  2. Select F22 (Display entire field), you will see the full name of this port, APPCoverTCPIP. These ports represent the MPTN daemons that are active and running on the AS/400.

Check Firewalls and Other Devices

Confirm with your network administrator that firewalls and any other intermediary devices between your PC and the AS/400 are configured to pass traffic for TCP port 397. MPTN uses this TCP port to communicate.

If you have not previously used MPTN to connect to your AS/400, your network administrator may need to configure intermediary devices to pass traffic for this port. Ask your system administrator to check that your user security is at 30 or higher.

Check TCP/IP and LAN Adapter on the AS/400

For more information on verifying that TCP/IP is configured properly, installing TCP/IP on an AS/400, and checking to see if your Ethernet or Token-Ring adapter is properly installed, see KB 7021470.

Additional Information

Legacy KB ID

This document was originally published as Attachmate Technical Note 1070.