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Troubleshooting CIP TN3270 Problems

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Document ID: 12320


Contents

Introduction
Before You Begin
      Conventions
      Prerequisites
      Components Used
Possible Symptoms and Suggested Actions
      DLUR Hung in RESET State
      Unable to Get a Client Connection to TN3270 Server
      D NET,DLURS Shows DLUR Session in RESET State
      Garbled Screens Appear
      LU Gets Stuck in PARCV State
      Troubleshooting Case Studies
Related Information

Introduction

This document explains how to troubleshoot some of the more common Channel Interface Processor (CIP) TN3270 problems. It also includes specific troubleshooting case studies.

Before You Begin

Conventions

For more information on document conventions, see the Cisco Technical Tips Conventions.

Prerequisites

There are no specific prerequisites for this document.

Components Used

This document is not restricted to specific software and hardware versions.

The information presented in this document was created from devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If you are working in a live network, ensure that you understand the potential impact of any command before using it.

Possible Symptoms and Suggested Actions

DLUR Hung in RESET State

If the Dependent LU Requester (DLUR) is hung in the RESET state, perform the actions below.

  1. Verify that the symptom is CP-CP session O.K on the Virtual Telecommunications Access Method (VTAM) display. Issue the sho ext chan x/2 tn3270 command and verify that the output is DLUR is in RESET state.

  2. Check the NODETYPE= and CONNTYPE= parameters in the VTAM Startup Options. The NODETYPE and CONNTYPE should be Advanced Peer-to-Peer Networking (APPN) instead of Low Entry Networking (LEN). The default for CONNTYPE=APPN.

  3. Make sure the ran opened in the XCA Major Node (MN) corresponds to the correct adapter/desination MAC address for the connection.

  4. The SAPADDR parameter in XCA MN is not 4, and downstream devices (SDLLC, QLLC) should default to 4. Failure symptoms show up as no response to IEEE (NULL) XID, however, do get a response to TEST.

Unable to Get a Client Connection to TN3270 Server

The following error message is logged:

%CIP1-1-MSG:
%TN3270S-1-NO_DYN_ACTLU_REQ_RCVD: 
No ACTLU REQ received on LU TSYSPU.3

If you get this error message, perform the actions below.

  1. It appears that there was no response to the Network Management Vector Transport (NMVT) (Reply-PSID), which is driving the dynamic Logical Unit (LU) definition.

  2. Verfiy that the LUGROUP MN is up by issuing the following VTAM command:

    D NET,ID=lugroup_name,E

    If it does not exist, you have not yet brought up the LUGROUP MN.

  3. Verify that the DDDLU exit is active by issuing the following VTAM command:

    D NET,EXITS

    The output should indicate that ISTEXCSD is active and has exit ISTEXCSD in place.

D NET,DLURS Shows DLUR Session in RESET State

This should not appear at all. The attempt to reconnect DLUR amy be rejected with sense 08050000. If so, perform the steps below.

  1. Verify that APAR OW20389 is integrated in VTAM. If APAR OW20389 addressed the problem, the link between Network Node (NN) and End Node (EN) is forced down while carrying the DLUR-DLUS session. The session is not properly cleaned up in DLUS.

  2. If APAR OW20389 is not applied, follow the steps below to bypass the problem.

    • Restart VTAM.

    • Change the name of the DLUR.

Garbled Screens Appear

When clients acting as an IBM 3270 Model 3, 4, or 5 connect to the Information Management System (IMS) through a CIP TN3270 server, a garbled screen may result. If so, perform the steps below.

  1. When IMS sends an ERASE WRITE message, it expects the screen to be 27 x 132. The client expects the screen to be 24 x 80, so the output screens get corrupted.

  2. Make sure that you have read the information on bug ID CSCdi77802 and applied the solution. Use the Bug ToolKit (registered customers only) for more information on this bug ID. The TN3270 server must detect the discrepancy and translate between ERASE WRITE and ERASE WRITE ALTERNATE messages.

    IMS does not perform a read partition query to determine the terminal's screen size characteristics. If IMS receives a LOGMODE message with a primary screen size of 24 x 80 (MOD2) and an alternate screen size of 27x132 (MODS), IMS sets the bind to both primary and alternate screen size of 27x132 (MOD 5). The TN3270 server does a +RSP to the bind, but the TN3270 client does not know that the primary screen size has changed. The client expects a primary screen size of MOD2, but the application (IMS) has changed the primary screen size to MOD5.

LU Gets Stuck in PARCV State

The LU may get stuck in the PARCV state while running the TN3270 DLUR function. This problem occurs when the following happens:

  • The LU is LOGAPPLd at the host,

  • DLUR is used.

  • The unbind-action is disconnected.

  • The client logs off .

If any of this occurs, perform the step below.

Recover by varying the LU inact/act from the host. Bypass by applying the APAR OW20254.

Troubleshooting Case Studies

For more information, refer to the following case studies:

Related Information

Updated: Sep 09, 2005 Document ID: 12320