Troubleshooting
Problem
Your CICS Transaction Server (CICS TS) region is not responding, and no one is able to logon. When you use your CICS monitor software to look at the region, you see that the CSNE task is in an IRLINK wait. This could start occurring after you change some of your CICS resources from local to remote, or you change your node error program (NEP) to access remote resources.
Cause
The CSNE task has issued commands that cause Intersystem Communication (ISC). If the CSNE task is asked to perform a function that requires resources from another CICS region, it will function ship the request. This will cause the CSNE task to be suspended in an IRLINK wait. One way this can occur is if your locally written NEP writes to a file that is remotely owned. It can also occur if the NEP issues an EXEC CICS START command for a transaction that is defined as remote. Both of these restrictions are discussed in the CICS Customization Guide.
Most of the time you will not have any problem when doing this, as the remote region will respond quickly. However, if the remote region is unable to respond, or a network problem prevents the request from reaching the remote region, the CSNE task will suspend. This can prevent users from logging on to the region.
Originally, your NEP did not access remote resources. But as your CICS environment grows, you might move files to a file owning region (FOR), or move a set of transactions to a new application owning region (AOR). This can inadvertently introduce the problem by changing resources that CSNE accesses from local to remote.
ISV products can also introduce this problem. They often supply customized code for you to add to your local NEP. If their changes cause CSNE to access remote resources, the potential now exists for the region to hang.
Resolving The Problem
Remove EXEC CICS commands that cause CSNE to invoke ISC communication from the following:
- Locally written Node Error Programs (DFHZNEP)
- System exits, such as an ISV External Security Manager exit, that you have customized
This includes function shipping or START requests for remote transactions. Section Restrictions on the use of EXEC CICS commands under Writing your own node error program in the CICS TS V5.1 information center documents this and other restrictions.
If your local processing requirements necessitate that you start a remote transaction, you should start a local transaction that starts a remote one in turn. Likewise, if you need to access a remote file, you should consider starting a local transaction that would then access the remote file.
Product Synonym
CICS/VSE CICS VSE CICS/TS CICS TS CICS Transaction Server
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Document Information
Modified date:
05 January 2026
UID
swg21052093