Preventing Repeated APPC Session Activation Failures Event 18 (150959)


The information in this article applies to:

  • Microsoft SNA Server 2.0, when used with:
    • the operating system: Microsoft Windows NT
  • Microsoft SNA Server 2.1, when used with:
    • the operating system: Microsoft Windows NT
  • Microsoft SNA Server 2.11, when used with:
    • the operating system: Microsoft Windows NT
  • Microsoft SNA Server 3.0, when used with:
    • the operating system: Microsoft Windows NT
  • Microsoft SNA Server 4.0, when used with:
    • the operating system: Microsoft Windows NT
This article was previously published under Q150959

SUMMARY

When SNA Server is configured with independent APPC LU6.2 sessions, SNA Server will automatically initiate LU6.2 session negotiation with the remote system for each configured LU/LU/mode pair when the connection is started. The independent LU6.2 LUs require an initial SNA Service Manager (SNASVCMG) mode BIND between the LUs in order for session limit (CNOS) negotiation to take place.

If a BIND error is received on this mode, SNA Server will log the following Event 18:

NOTE: It will continue to retry.
Event 18

APPC session activation failure: BIND negative response or UNBIND
request received

Sense data = <sense data>
Connection = <connection name>
LU alias = <local LU alias>
PLU alias = <remote LU alias>
Mode name = SNASVCMG
If the remote system is not currently active (for example, if the remote system is CICS though the CICS region has been brought down for maintenance), the Event 18 will be logged for each BIND failure.

The SNA Server NOINITCNOS registry setting can be set to prevent these repeated Event 18 errors.

MORE INFORMATION

SNA Server supports a registry entry that disables automatic LU6.2 session negotiation using the NOINITCNOS registry setting, as documented in the SNA Server [ASCII 147]Reference Guide,[ASCII 148] page 195 (in Appendix C). This will cause SNA Server to perform LU6.2 session negotiation only when an application requests a conversation over an LU/LU pair. 
   HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/Snaservr
   /Parameters/ 

   NOINITCNOS: REG_SZ: YES
If this entry is not present in the registry, it defaults to No.
Modification Type:MinorLast Reviewed:11/18/2004
Keywords:kbnetwork kbusage KB150959
©2004 Microsoft Corporation. All rights reserved.