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Informix Error -5011: CSM: protocol error.

Cause and resolution

CSM: protocol error.

A CSM (Communications Support Module), in the database server or in the client, received a message that is not consistent with the CSM's protocol formats, with its internal state, or with both. The usual cause of this error is an internal message inconsistency, which indicates the receipt of a protocol data unit with an unknown format. This error can occur only during use of a CSM, and the cause can be a communications error, the use of incompatible versions of the CSM in the client and the database server, or inconsistent configurations of the client and database server CSMs.

If this error occurs during context setup (that is, at connection time), the connection establishment fails. If this error occurs after establishment of the connection, the connection is dropped.

Make sure that the release levels of the CSMs types match, and the configurations of client and database server CSMs match. If the problem recurs, contact IBM Informix Technical Support or the CSM vendor and have the following information available: CSS configuration files and sqlhosts information for both the client and the database server.

Oninit® Troubleshooting Guidance

Reasons / Common Causes

-5011 fires when a CSM (Communications Support Module) receives a message inconsistent with its protocol formats, its internal state, or both — per the official guidance, usually an internal message inconsistency indicating receipt of a protocol data unit with an unknown format.

  1. A communications error, per the official guidance — the first named cause.
  2. Incompatible CSM versions between client and database server, per the official guidance — the second named cause.
  3. Inconsistent CSM configurations between client and database server, per the official guidance — the third named cause.
Solutions / Resolution
  1. Make sure the release levels of the CSM types match, per the official guidance.
  2. Make sure the configurations of client and database server CSMs match, per the official guidance.
  3. If the problem recurs, contact IBM Informix Technical Support or the CSM vendor, per the official guidance, with the CSS configuration files and sqlhosts information for both sides available.
Examples
N/A

No specific triggering statement is documented beyond a communications error or a CSM version/configuration mismatch.

Diagnostic Checks
  1. Compare CSM release levels and configurations on the client and database server, and align them.
Related Errors / Related Topics
  • -5010 — "CSM: internal processing error." A related CSM error, about an internal fault the CSM can't self-diagnose, rather than a specific protocol-format inconsistency.
  • -5012 — "CSM: received message of unexpected type." A more specific version of this same class of error, where an internally consistent protocol data unit carries a message type the receiver can't handle.

A CSM received a protocol-inconsistent message — match CSM release levels and configurations between the client and database server.