XCOMM0780E Txpi 701: Received remote data block ... invalid EyeCatcher ...

Products

• XCOM Data Transport - z/OS
• XCOM Data Transport

Issue/Introduction

XCOMJOB TYPE=EXECUTE transfer fails with:

 16.52.28 JOB07298  XCOMM0785I STARTING TCP/IP CONNECTION TO PORT=08044, IP=##.##.#.#
 16.52.28 JOB07298  XCOMM0786I TCP/IP CONNECTION ESTABLISHED WITH DEST=**NONE**, PORT=08044, IP=##.##.#.#
 16.52.28 JOB07298  IGD103I SMS ALLOCATED TO DDNAME SYS00006              
 16.52.29 JOB07298  ##.##.#.#  #002000 AKNDTD42    XCOMM0402I REQUEST NUMBER 002000 ASSIGNED TO TRANSFER REQUEST 
 16.52.30 JOB07298  ##.##.#.#  #002000 AKNDTD42    XCOMM0126E FMH7 SENSE 00000000          
 16.52.30 JOB07298  XCOMM0780E Txpi  701: Received remote data block at 0X1F3C41FC starting with invalid EyeCatcher 0X32303235 (

Environment

XCOM™ Data Transport® for z/OS

Cause

"... invalid EyeCatcher" means XCOM received an unrecognized communication.

The message symptoms are similar to when a port scan is being done on the XCOM server started task port 8044. See article:  XCOMM0794E RECURSIVE ERROR DETECTED, TCP/IP LISTENER TERMINATED
However this is an XCOMJOB TYPE=EXECUTE, so the local XCOM server is not being used and the problem is not due to a port scan being done on it.  
The IP address and port being used must not be pointing to an XCOM instance on the remote side i.e. some other software is listening on port 8044 which is responding to the XCOM header with data that begins with an ASCII "2025" (x'32303235').

Resolution

The output job log also does not show any IPPORT parameter specified in the SYSIN01 and so it defaults to the CONFIG member value 8044.
If the target XCOM Server for the transfer is not listening on port 8044 ensure that the correct value for IPPORT is specified in the SYSIN01.