Red Alert for all TCPIP users on z/OS 1.11

Here's a Red Alert for all TCPIP users on z/OS 1.11 :

Abstract:
A logic error in the base TCPIP code of z/OS 1.11 can cause applications using ASYNCIO Writes to be driven twice. This can affect various applications and subsystems using z/OS TCPIP ASYNCIO on the sending side, such as Websphere MQ, JES and non-IBM products.

Description:
A logic error in TCPIP on z/OS 1.11 can cause applications using ASYNCIO Writes to be driven twice. The application data presented on the socket write operation is sent over the TCP connection twice, thus corrupting the data stream. This can affect various applications and subsystems using z/OS TCPIP ASYNCIO on the sending side, such as Websphere MQ, JES and non-IBM products. Please see APAR PM08514 for the details and symptoms that may result.

Recommended Action:
All z/OS 1.11 users should install the APAR fix for PM08514 that is currently available from IBM Support. This APAR does not apply to prior z/OS releases.

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