During normal processing, COMMON SERVICES TASK CCITCPGW receives an error.

Products

• COMMON SERVICES FOR Z/OS
• 90S SERVICES
• Common Services

Issue/Introduction

CCITCPGW/CCISSLGW may start to receive CAS9899E - Task XX - Error: Invalid CTH header received.

13.00.09 STCnnnn CAS9855I Task nn has connection from (##.###.###.###):nnnnn 
13.00.17 STCnnnn CAS9855I Task nn has connection from (##.###.###.###):nnnnn

then continuous:

13:00.17 STCnnnn CAS9899E Task ## - Error: Invalid CTH header received 
13.00.17 STCnnnn CAS9890E - Vers: ## Cpu: #

Environment

Common Services using CCITCPGW or CCISSLGW

Cause

CCITCPGW is one of Broadcom's TCPIP APPLICATIONS. 

 

An outside program is trying to connect to this mainframe (from another mainframe, windows or unix), using port 7000 which is the default port for CCITCPGW.

Addr = ###.###.##.# 

Somewhere in this outside program, it also has the port number that CCITCPGW is using,  7000. 

 

CCITCPGW is attempting to use this unrecognized data, transmitted by this outside program.

This results in CAS9899E TASK nnn ERROR: INVALID PACKET HEADER RECEIVED. 

INVALID CTH will always be some non cci user trying to send data to CCI (in error). 

 

Then stops, because the user program cancels... 

 

There is no way for CCI support to block anyone who tries this. 

 

Resolution

If CCITCPGW is active, an outside program cannot use port 7000.