Cisco IOS Software Releases 11.0

Field Notice: CSNA Nodes/Connections Go "INOP"

October 23, 1997


This field notice describes a cache problem with CSNA (or TN3270 Server using XCA connection) nodes/connections going "INOP."

Microcode Affected

  • cip22-23 for Cisco IOS 11.0BT, 11.1 and 11.2

  • cip22-24 for Cisco IOS 11.0BT, 11.1 and 11.2

  • cip24-1 for Cisco IOS 11.2BC

  • cip25-3 for Cisco IOS 11.3ED

  • interims; 206-224, 206-230, 206-240, 210-11, 210-20, 212-30, 212-31

The following hardware is affected when used in conjunction with the CIP Microcode mentioned above and the CSNA/TN3270 (using XCA) feature:

  • cx-cip-pca1, cx-cip-pca2

  • cx-cip-eca1, cx-cip-eca2

  • cx-cip-ecap1

  • cx-cip2-pca1, cx-cip2-pca2

  • cx-cip2-eca1, cx-cip2-eca2

  • cx-cip2-ecap1

Problem Description

This problem occurs when a block is constructed and sent to the channel that contains multiple frames and the last frame (including command header) is shorter than 31 bytes. This has been observed only with inbound flow control commands because this is the only inbound command with a length that short. It will not happen with a data frame because the data indication command header is 32 bytes.

Problem Symptoms

The host XCA node goes down, or attached PUs or LUs go "INOP" (message IST259I INOP RECEIVED FOR XXXXXXXX CODE = 02). In many cases where large numbers of LUs are being activated, this happens shortly after activating the XCA major node.


Revert to a previous CIP microcode version, or install the next release that does not contain this problem.


This problem is fixed in cip22-25, cip24-2, and cip25-4. If this code is not available on CCO, contact the Cisco Technical Assistance Center (TAC) and obtain an interim level of CIP microcode.

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods: